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Secundaria Ages 11-13
Go deeper: algebra, physics, coding, nature and longer reads.
➗ Matemáticas
📐Angles in a TriangleDiscover why the angles in a triangle always add up to 180°, how to find a missing angle, the exterior angle rule, and i📐Area and PerimeterLearn area and perimeter the clear way: the difference between them, formulas for rectangles, squares and triangles, uni📐Area of a TriangleMaster the area of a triangle: why the formula is ½ × base × height, how to find the perpendicular height, worked exampl📐Area of Parallelograms and TrapeziumsFind the area of parallelograms and trapeziums with clear formulas, why they work, the perpendicular-height rule, and st📊Averages from a Frequency TableFind the mean, median and mode from a frequency table. Learn the fx column method, the cumulative count for the median, 🥤Capacity and Volume in LitresA middle-school math lesson on capacity and volume: litres and millilitres, reading measuring jugs, the link between 1 l⭕Circles: Circumference and AreaLearn the parts of a circle and master circumference and area using pi: clear formulas, full worked examples, the radius🧮Collecting Like TermsMaster collecting like terms in algebra: spot matching terms, add and subtract their coefficients, handle negatives and 🔄Converting Fractions, Decimals and PercentagesConvert between fractions, decimals and percentages with confidence: clear rules for every direction, a handy conversion🔁Converting Metric UnitsA middle-school math lesson on converting metric units of length, mass and capacity: the prefix staircase, multiplying a🧭Coordinates in Four QuadrantsPlot and read coordinates in all four quadrants using positive and negative x and y values. Learn the quadrant signs, th🔢Decimals ExplainedUnderstand decimals clearly: place value of tenths and hundredths, reading and comparing decimals, and adding, subtracti➗Dividing DecimalsA middle-school lesson on dividing decimals: divide by a whole number, turn a decimal divisor into a whole number, and u➗Dividing FractionsMaster dividing fractions with the keep-change-flip method: multiply by the reciprocal, simplify, and divide whole and m🔢Divisibility RulesQuick divisibility tests for 2, 3, 4, 5, 6, 8, 9, 10 and 11 — how to tell if a number divides exactly without doing the ✅Estimation and Checking AnswersLearn to estimate answers and check your work: rounding to estimate, the inverse operation check, the does-it-make-sense📦Expanding BracketsLearn to expand brackets in algebra using the distributive law. Step-by-step worked examples with negative signs, two br🎲Experimental vs Theoretical ProbabilityCompare experimental and theoretical probability using relative frequency. Learn to estimate chance from trials, spot bi🔢Exponents and PowersMaster exponents and powers: what a base and exponent mean, squares and cubes, the laws of exponents, the power of zero,📏Graphing Inequalities on a Number LineShow linear inequalities on a number line: open vs closed circles, which way the arrow points, solving first, and readin📏Imperial and Metric UnitsA middle-school math lesson comparing imperial and metric units: inches, feet, miles, pounds, pints versus metric, with ⚖️InequalitiesUnderstand inequalities: read the four symbols, solve one- and two-step inequalities, plot solutions on a number line, a🍰Introduction to FractionsUnderstand fractions clearly: numerators and denominators, equivalent fractions, comparing and simplifying, plus worked ➖Introduction to Integers (Negative Numbers)Meet the integers: positive and negative whole numbers. Learn the number line, absolute value, and the rules for adding,📈Line GraphsA middle-school math lesson on line graphs: plot points, read values, interpret trends and gradients, handle two lines, 🔗Lowest Common Multiple and Highest Common FactorLearn the LCM and HCF: how to find the lowest common multiple and highest common factor using lists and prime factors, p📊Mean, Median, Mode and RangeMaster the four key statistics: learn to calculate mean, median, mode and range step by step, when to use each one, and ✖️Multiplying DecimalsA middle-school lesson on multiplying decimals: multiply as whole numbers then place the decimal point by counting decim✖️Multiplying FractionsMaster multiplying fractions: multiply tops, multiply bottoms, simplify, and handle whole and mixed numbers. Worked exam🔢Number Sequences and the nth TermLearn to find the nth term rule of a linear sequence. Step-by-step worked examples: find the common difference, build th➖Operations with Negative NumbersMaster adding, subtracting, multiplying and dividing negative numbers: the sign rules, using a number line, and double-n🧮Order of Operations (BODMAS/PEMDAS)Master the order of operations with BODMAS and PEMDAS: brackets, indices, division, multiplication, addition and subtrac📈Percentage Increase and DecreaseA middle-school lesson on percentage increase and decrease using multipliers: build the multiplier, apply it in one step%Finding a Percentage of an AmountLearn to find a percentage of an amount three ways: using 10% and 1% building blocks, fractions, and decimal multipliers🏷️Percentages in Real Life (Discounts and Tax)Use percentages in everyday situations: work out discounts, sales prices, sales tax and VAT, tips, and percentage increa💯Percentages Made EasyMaster percentages step by step: what percent means, finding a percent of a number, percentage increase and decrease, an📐Perimeter of Compound ShapesLearn to find the perimeter of compound (composite) shapes: how to find missing side lengths, work systematically around🥧Pie ChartsA middle-school math lesson on pie charts: read sectors, work out angles and percentages, draw your own pie chart, find 🌳Prime FactorisationLearn prime factorisation: how to break any number into its prime building blocks using a factor tree, write the answer ⚖️Ratio and Proportion ProblemsMaster ratio and proportion word problems: sharing amounts, scaling recipes, map scales, unit rates, and the unitary met⚖️Ratios and ProportionsUnderstand ratios and proportions: how to write and simplify a ratio, find equivalent ratios, scale recipes, and solve p🔄Rotation and TranslationLearn two key transformations: rotation (turning a shape about a centre by an angle) and translation (sliding a shape). 🔟Rounding to Significant FiguresLearn how to round numbers to significant figures: identifying significant figures, the rounding rule, handling zeros an📏Scaling: Times as BigUnderstand multiplication as scaling — making quantities 'times as big' or 'times as small'. Learn scale factors, how to🧹Simplifying ExpressionsLearn to simplify algebraic expressions by collecting like terms. Step-by-step worked examples covering signs, multiple ✂️Simplifying Fractions Using the HCFA middle-school lesson on simplifying fractions in one step using the highest common factor: find the HCF, divide top an⚖️Solving Equations with BracketsLearn to solve linear equations that contain brackets. Step-by-step worked examples: expand, collect like terms, balance🧮Solving Two-Step EquationsLearn to solve two-step equations the reliable way: undo operations in reverse order, keep both sides balanced, handle n🟦Square Numbers and Square RootsUnderstand square numbers and square roots: how squaring works, perfect squares, finding and estimating roots, and where🔁Substituting into FormulasLearn to substitute numbers into algebraic formulas. Step-by-step worked examples with brackets, powers, negative number📦Surface Area and VolumeLearn surface area and volume of cubes, cuboids, prisms and cylinders with clear formulas and full worked examples, plus📈The Coordinate PlaneLearn the coordinate plane: the x-axis and y-axis, the origin, ordered pairs (x, y), the four quadrants, and how to plot📐The Distributive LawUnderstand the distributive law: how multiplication spreads over addition and subtraction, a(b+c)=ab+ac, using it for me📏The Range and OutliersLearn how the range measures spread, why it is sensitive to outliers, and how to spot and handle outliers in data. Worke🚆Time Durations and TimetablesA middle-school math lesson on working out elapsed time and reading bus and train timetables: counting time on in steps,🔲Two-Way TablesMaster two-way tables: read rows, columns and totals, fill in missing values, and pull out probabilities. Clear worked e📐Drawing and Measuring Angles with a ProtractorLearn to measure and draw angles with a protractor: line up the centre and baseline, read the correct scale, avoid the u⭕Venn Diagrams and SetsLearn Venn diagrams and sets: what a set is, union and intersection, the universal set and complement, reading overlappi✍️Writing Algebraic ExpressionsLearn to turn words into algebra: choose a variable, translate phrases like 'three more than' or 'twice a number', and w
⚛️ Física
🚀Acceleration ExplainedA middle-school physics lesson on acceleration: what it means, the acceleration formula, units of m/s², deceleration, gr⚖️Balanced and Unbalanced ForcesA middle-school physics lesson on balanced and unbalanced forces: resultant force, free-body diagrams, how unbalanced fo🤸Centre of Mass and BalanceA middle-school physics lesson on centre of mass and balance: what the centre of mass is, how to find it, why an object 🔥Conduction, Convection and RadiationA middle-school physics lesson on the three ways heat travels: conduction, convection and radiation. Worked examples, re📈Distance-Time GraphsA middle-school physics lesson on distance-time graphs: how to read them, what the gradient means, calculating speed fro🦇Echoes and UltrasoundA middle-school physics lesson on echoes and ultrasound: how sound reflects, how to calculate distance from echo time, w⚡Electric Charge, Conductors and InsulatorsA middle-school physics lesson on electric charge: protons and electrons, conductors vs insulators, charging by friction🔌Electricity Basics: Circuits and CurrentA middle-school physics lesson on electricity: electric charge, current, voltage, resistance, series and parallel circui♻️Energy Efficiency and TransfersA middle-school physics lesson on energy transfers and efficiency: conservation of energy, useful vs wasted energy, Sank⚡The Many Forms of EnergyA middle-school physics lesson on forms of energy: kinetic, potential, thermal, chemical, electrical, light and sound, e🛞Friction: The Force That Slows Things DownA physics lesson on friction for ages 9-13: learn what friction is, why surfaces grip, how lubricants and drag work, whe🔥Heat and How It TravelsA middle-school physics lesson on heat: temperature vs heat energy, and the three ways heat travels — conduction, convec🏠Household Electricity and SafetyA middle-school physics lesson on household electricity: AC mains, the live, neutral and earth wires, how fuses, earthin🚲How a Bicycle WorksA middle-school physics lesson on how a bicycle works: balance and gyroscopic effect, gears and force, friction in brake🧊How a Fridge Keeps Food ColdA middle-school physics lesson on how a refrigerator works: evaporation cooling, the refrigerant cycle, compressor and c🔍How Lenses WorkA middle-school physics lesson on how lenses work: convex and concave lenses, refraction, focal length, real and virtual🎸How Musical Instruments Make NotesA middle-school physics lesson on how instruments make notes: vibrations, resonance, standing waves, why strings and pip🏭How We Generate ElectricityA middle-school physics lesson on generating electricity: turbines, generators and electromagnetic induction, fossil fue🪙Levers and MomentsA middle-school physics lesson on levers and moments: the law of the lever, the principle of moments, pivots, effort and🪝Measuring Forces with SpringsA middle-school physics lesson on measuring forces with springs and newton-meters: Hooke's law, F = kx, the elastic limi🛰️Orbits and SatellitesA middle-school physics lesson on orbits and satellites: how gravity keeps moons and satellites in orbit, why they don't🛢️Pressure and HydraulicsA middle-school physics lesson on pressure and hydraulics: the pressure formula, why pressure spreads through liquids, P🌊Pressure in Liquids and GasesA middle-school physics lesson on pressure in fluids: what pressure is, why it increases with depth, atmospheric pressur🌍Seismic Waves: P-waves and S-wavesA middle-school physics lesson on seismic waves: how earthquakes make P-waves and S-waves, why P-waves arrive first, how🔋Series and Parallel CircuitsA middle-school physics lesson on series and parallel circuits: how current, voltage and brightness behave in each, work🏃Speed, Distance and TimeA middle-school physics lesson on speed, distance and time: the speed formula, average vs instantaneous speed, units, di📊Speed-Time GraphsA middle-school physics lesson on speed-time graphs: reading them, finding acceleration from the gradient, distance from⭐The Life Cycle of StarsA middle-school physics lesson on the life cycle of stars: how stars are born in nebulae, shine by nuclear fusion, and d⚛️The Particle Model of MatterA middle-school physics lesson on the particle model of matter: tiny moving particles, how they explain solids, liquids ✈️The Physics of FlightA middle-school physics lesson on how planes fly: the four forces of flight (lift, weight, thrust, drag), how wings make🪐The Solar System and GravityA middle-school physics lesson on the solar system and gravity: the Sun, planets, orbits, why we have day and night and ⚡Voltage, Current and ResistanceA middle-school physics lesson on voltage, current and resistance and how Ohm's law links them. Worked V=IR examples, th〰️Wavelength, Frequency and AmplitudeA middle-school physics lesson on wavelength, frequency and amplitude: what each wave property means, the wave equation 🌊Waves and VibrationsA middle-school physics lesson on waves and vibrations: transverse and longitudinal waves, wavelength, frequency, amplit⚖️Weight vs MassA middle-school physics lesson on the difference between weight and mass: why mass stays the same everywhere, how weight🌤️Why the Sky Is BlueA middle-school physics lesson on why the sky is blue: how sunlight is made of colours, how air scatters blue light most
🌿 Naturaleza
🧪Acids and BasesAcids and bases explained for middle-school students: the pH scale, how acids and bases react, neutralisation, indicator🌬️Air Pressure and WindDiscover what air pressure is and how it creates wind. Learn about high and low pressure, the barometer, why air moves a🦷Animal Teeth and DietsExplore how animal teeth match their diets for middle-grade students: incisors, canines and molars, why herbivore and ca⚛️Atoms and MoleculesAtoms and molecules explained for middle-school students: protons, neutrons and electrons, elements and the periodic tab🌈Build a Density TowerA middle-school science lesson and safe experiment: stack liquids into a colourful density tower, drop in objects that f🪰Carnivorous Plants: The Plants That Catch AnimalsCarnivorous plants explained for middle school: how Venus flytraps, pitcher plants and sundews trap and digest insects, 🔬Cells: The Building Blocks of LifeCells explained for students: the smallest unit of life, plant vs animal cells, the parts of a cell and their jobs, how ⚗️Chemical Reactions and Signs of ChangeChemical reactions explained for middle-school students: how reactants turn into new products, the five signs a reaction🪸Coral Reefs and Why They MatterCoral reefs explained for middle-school students: how corals build reefs, the animals that depend on them, why reefs mat🌋Earthquakes and TsunamisEarthquakes and tsunamis explained for middle school: how tectonic plates cause earthquakes, how seismic waves are measu🧬Elements, Compounds and MixturesElements, compounds and mixtures explained for middle-school students: the difference between a pure element, a compound🦅Food Chains and EcosystemsUnderstand food chains, food webs and ecosystems: producers, consumers, predators and decomposers. Real examples, energy🌌Galaxies and the Milky WayGalaxies and the Milky Way explained for ages 11-14: what a galaxy is, the shape and size of our Milky Way, spiral, elli🫁Gas Exchange in the LungsA middle-school lesson on gas exchange: how the alveoli swap oxygen for carbon dioxide, why the lungs have a huge surfac🧬Hormones and Growing UpA middle-school lesson on hormones: the chemical messengers that control growth, energy, mood and puberty, the main glan🦇How Caves FormHow caves form, explained for middle school: solution caves dissolved by acidic water, stalactites and stalagmites, sea 🦴How Fossils FormHow fossils form, explained for middle school: the step-by-step process of fossilisation, the different types of fossils🌵How Plants Defend ThemselvesHow do plants protect themselves without moving? A middle-school lesson on thorns, stinging hairs, poisons, bad tastes a🚀How Rockets WorkA clear lesson on rocket science for ages 11-14: Newton's third law, thrust and exhaust, why rockets carry their own oxy🌀Hurricanes and TornadoesCompare hurricanes and tornadoes: how each forms, why they spin, how scientists measure them, real-world examples, safet🪐Jupiter and Saturn: The Giant PlanetsA lesson on the gas giants for ages 11-14: why Jupiter and Saturn are so huge, the Great Red Spot, Saturn's rings, their🌍The Layers of the AtmosphereExplore the five layers of Earth's atmosphere: troposphere, stratosphere, mesosphere, thermosphere and exosphere. Where 🍃Lichens: Nature's Air DetectivesA middle-school biology lesson on lichens: the fungus-and-algae partnership, how they survive almost anywhere, why they 🔴Mars: The Red PlanetA clear lesson on Mars for ages 11-14: why it looks red, its thin air, the giant volcano Olympus Mons, the great canyon 🔩Metals and Non-MetalsMetals and non-metals explained for middle-school students: how to tell them apart by shine, conductivity, malleability 🌿Mosses and Ferns: The Ancient Plants Without FlowersMosses and ferns explained for middle school: ancient plants with no flowers or seeds, how they reproduce with spores, w🌊Natural Disasters: Floods, Droughts and StormsNatural disasters explained for students: what causes floods, droughts and storms, why they happen, how scientists predi🌿Photosynthesis ExplainedPhotosynthesis explained for middle school: how plants use sunlight, water and carbon dioxide to make glucose and oxygen⚡Renewable and Non-Renewable EnergyRenewable and non-renewable energy explained for students: fossil fuels, solar, wind, water and nuclear power, why energ🦎Reptiles and Amphibians: What's the Difference?Reptiles vs amphibians explained for middle-grade students: skin, eggs, breathing, life cycles and habitats compared, wi🐻Tardigrades: The Toughest Animals on EarthA middle-school biology lesson on tardigrades (water bears): microscopic animals that survive boiling, freezing, drought🔭Telescopes and Studying SpaceHow telescopes work and how scientists study space, for ages 11-14: refractors and reflectors, light-gathering and magni🧠The Brain and Nervous SystemA middle-school lesson on the nervous system: neurons, the brain's main regions, the spinal cord, reflexes, and how elec♻️The Carbon CycleThe carbon cycle explained for students: how carbon moves between the air, living things, oceans and rocks, the role of 🫀The Circulatory System: Heart and BloodHow the heart and blood work, for middle school: the four heart chambers, arteries, veins and capillaries, what blood ca🍽️The Digestive SystemHow the digestive system works, explained for middle school: mouth, stomach, small and large intestine, enzymes and nutr🌍The Greenhouse EffectUnderstand the greenhouse effect: how greenhouse gases trap heat and keep Earth warm, why human activity is strengthenin🦴The Human SkeletonThe human skeleton explained for students: the 206 bones, what they are made of, the jobs of the skeleton, joints and mu🛰️The International Space StationA lesson on the International Space Station for ages 11-14: what the ISS is, how it orbits Earth, why astronauts float, 🫘The Kidneys and Keeping Clean InsideA middle-school lesson on the urinary system: how the kidneys filter your blood, make urine, balance water and salts, an🌕The Moon LandingsThe story of the Apollo Moon landings for ages 11-14: the space race, Apollo 11 and the first steps in 1969, what astron🧪The Periodic Table for BeginnersThe periodic table explained for middle-school students: what elements are, how the table is organised into groups and p🥬The Red Cabbage pH IndicatorA middle-school chemistry lesson and safe kitchen experiment: make a colour-changing pH indicator from red cabbage, test🫁The Respiratory System: How We BreatheHow breathing works, for middle school: the path of air through nose, trachea and lungs, the alveoli, gas exchange, the 🪨The Rock CycleThe rock cycle explained for middle school: how igneous, sedimentary and metamorphic rocks form and change over millions🦓The Savanna Grassland BiomeThe savanna biome explained for middle-school students: its wet and dry seasons, grasses and scattered trees, famous Afr🫀The Systems of the Human BodyExplore the human body systems: circulatory, respiratory, digestive, nervous, skeletal and muscular systems explained fo🪨The Three Types of RocksA deeper look at igneous, sedimentary and metamorphic rocks for middle school: how each forms, real rock examples, cryst🍊Vitamins and MineralsA middle-school lesson on micronutrients: what vitamins and minerals are, the jobs of key ones like vitamin C, vitamin D🏞️Weathering and ErosionWeathering and erosion explained for middle school: how rock breaks down and gets carried away, the difference between t🦆Wetlands: Nature's Water FiltersWetlands explained for middle-school students: what marshes, swamps and bogs are, how they clean water and stop floods,
📖 Cuentos
🏜️Echoes in the CanyonAn original adventure story for ages 10-13: two siblings lost in a desert canyon learn to listen, work together, and fol🔔The Bell That Rang in ReverseAn original mystery for ages 11-13: when a village bell starts ringing backwards, Wren follows the sound to uncover a se🕰️The Clock That Ran BackwardsAn original mystery for ages 11-13: a strange clock in a repair shop runs backwards, and Mira's investigation reveals a 🕰️The Clockmaker's SecretAn original middle-grade short story for ages 10-13: an apprentice inherits her grandfather's mysterious clock shop and 🐦The Clockwork BirdAn original story for ages 10-13: a young inventor mends a broken clockwork bird and learns that real songs come from th📓The Code in the Old DiaryAn original mystery for ages 11-13: an old diary full of strange symbols leads Priya to crack a secret code and solve a 🔥The Firebird and Prince IvanA retelling of the classic Russian folk tale of the Firebird, Prince Ivan, the Grey Wolf and the Princess Helena, for ag🦎The Fossil That BlinkedAn original sci-fi mystery for ages 11-13: when a fossil in the school museum blinks back at her, Noor uncovers a creatu🌱The Garden on the Space StationAn original sci-fi story for ages 11-13: when a space station's garden starts dying, young Leo solves the mystery and le⭐The Girl Who Mapped the StarsAn original story for ages 10-13: a curious girl in a lighthouse town charts the night sky, faces doubters, and helps lo🌱The Greenhouse on Platform ZeroAn original sci-fi story for ages 11-13: on a crowded space station, Idris discovers a forgotten greenhouse that may be ⚙️The Inventor's ApprenticeAn original story for ages 10-13: a stubborn apprentice wants to build something brilliant on her first day, but learns 🎶The Island of Forgotten SongsAn original story for ages 10-13: a quiet girl sails to a vanishing island where every tune the world has forgotten is k📚The Last Library on MarsAn original sci-fi story for ages 11-13: on a struggling Mars colony, a girl fights to save a forgotten library and disc🌌The Legend of the Northern LightsA retelling of the legends of the Northern Lights from Arctic and Nordic peoples, for ages 10-13, with a thoughtful mora🏛️The Museum of Impossible ThingsAn original sci-fi mystery for ages 11-13: a museum's impossible exhibits hide a secret, and Jonah's curiosity uncovers 📚The Mystery of the Old LibraryAn original mystery story for ages 10-13: Maya and Theo follow hidden clues through a dusty old library to uncover a kin🪐The Orchard Beneath EuropaA thoughtful sci-fi story for ages 10-13 about Yara, a girl on a research station under the ice of Jupiter's moon, who d🏞️The River That Ran UphillAn original story for ages 10-13: when a village's river mysteriously flows backward up the mountain, a curious boy foll📡The Signal from Station NineAn original sci-fi mystery for ages 11-13: aboard an abandoned space station, young engineer Reza chases a repeating sig🛗The Thirteenth-Floor ButtonAn original fantasy mystery for ages 11-13: Priya presses an elevator button for a floor that shouldn't exist and steps 📷The Thirty-Second PhotographA clever mystery story for ages 10-13 about Jonas, who inherits an old camera that photographs thirty seconds into the f🐴The Trojan HorseA retelling of the legend of the Trojan Horse and the fall of Troy for ages 10-13, with a moral about cleverness and a c🏞️The Vanishing LakeAn original mystery for ages 11-13: when their town's lake disappears overnight, two friends follow the clues undergroun
📚 Libros
✈️A Short History of FlightA free online non-fiction book for ages 9-12: the story of flight from early dreamers and hot air balloons to the Wright⚕️A Short History of MedicineA free non-fiction mini-book for ages 11-14: the story of medicine from ancient healers to germs, vaccines, antibiotics 🚀A Short History of Space ExplorationA free non-fiction mini-book for kids: from the first rockets and Sputnik to the Moon landings, Mars rovers and the sear🕉️Ancient IndiaA free online non-fiction history book for ages 9-13 about Ancient India: the Indus Valley cities, the Vedic age, the Ma🔭Astronomers Who Mapped the SkyA free non-fiction book: meet Copernicus, Galileo, Kepler, Caroline Herschel, Henrietta Leavitt, Edwin Hubble, Cecilia P🌎Climate Zones and Biomes of the EarthA free non-fiction geography book for ages 10-13: explore the Earth's climate zones and great biomes — rainforests, dese🌋Earthquakes and the Restless EarthA free non-fiction geography book for ages 10-13: discover why the ground shakes — how the Earth's tectonic plates move,✍️Famous Writers Who Shaped LiteratureA free non-fiction book: meet Homer, Shakespeare, Jane Austen, Dickens, Tolstoy, Twain, Achebe and Toni Morrison, and th🏙️Great Cities of the WorldA free non-fiction geography book for ages 10-13: explore the world's great cities — how cities grow, why they sit where🎼Great Composers of Classical MusicA free non-fiction book: meet Bach, Mozart, Beethoven, Chopin, Tchaikovsky, Clara Schumann, Stravinsky and Florence Pric💡Great Inventions That Changed the WorldA free non-fiction mini-book for kids: discover the wheel, printing press, electricity, the telephone, flight and other 🌍Great Kingdoms of AfricaA free online non-fiction history book for ages 9-13 about the great kingdoms of Africa: Aksum, Ghana, Mali, Songhai, Gr➗Great Mathematicians and Their IdeasA free non-fiction book: meet Pythagoras, Euclid, Archimedes, al-Khwarizmi, Newton, Gauss, Ramanujan and Emmy Noether, a🌉How Bridges and Buildings Stand UpA free non-fiction mini-book on structural engineering for kids: forces, arches, beams, trusses, suspension bridges, fou🧠How Your Brain WorksA free non-fiction mini-book for ages 11-14: discover neurons, memory, emotions, the senses and sleep, and learn how you🧭Legendary Explorers of the PolesA free non-fiction book: meet Nansen, Amundsen, Scott, Shackleton, Peary, Henson, Matthew Henson's Arctic feats and Ann 🌍Legendary Leaders and ChangemakersA free non-fiction book for ages 10-13: meet leaders and changemakers like Mandela, Gandhi, Lincoln, Wangari Maathai, El🏰Life in Medieval TimesA non-fiction history book for ages 10-13 about the Middle Ages: the feudal system, castles and knights, peasants and to🧭Maps and NavigationA free non-fiction geography book for ages 10-13: discover how maps work, how to read scale, symbols and grid references🎤Musicians Who Changed MusicA free non-fiction book: meet Louis Armstrong, Ella Fitzgerald, Aretha Franklin, The Beatles, Bob Dylan, Jimi Hendrix, B🤔Philosophers Who Asked Big QuestionsA free non-fiction book: meet Socrates, Plato, Aristotle, Confucius, Hypatia, Descartes, Mary Wollstonecraft and Simone 🩺Pioneering Doctors Who Saved LivesA free non-fiction book: meet Hippocrates, Edward Jenner, Florence Nightingale, Louis Pasteur, Joseph Lister, Marie Curi🏅Sporting Heroes and Their TriumphsA free non-fiction book: meet Jesse Owens, Muhammad Ali, Pelé, Nadia Comaneci, Serena Williams, Usain Bolt, Simone Biles🧭The Age of ExplorationA non-fiction history book for ages 10-13 on the Age of Exploration: why Europeans sailed the oceans, Columbus and da Ga🐉The Ancient ChineseA non-fiction history book for ages 10-13 on ancient China: the great dynasties, the first emperor, the Great Wall, silk🔺The Ancient EgyptiansA non-fiction book for ages 10-13 on ancient Egypt: the River Nile, pharaohs and pyramids, gods and mummies, hieroglyphs🏛️The Ancient GreeksA non-fiction history book for ages 10-13 on ancient Greece: city-states, democracy in Athens, the warriors of Sparta, g🏟️The Ancient RomansA non-fiction history book for ages 10-13 on ancient Rome: from a city to a mighty empire, the army and roads, emperors,🧊The Arctic and AntarcticaA free non-fiction geography book for ages 10-13: explore the frozen poles — the Arctic Ocean of the north and the icy c🌊The Five Oceans of the WorldA free non-fiction geography book for ages 10-13: discover the five oceans of the world — Pacific, Atlantic, Indian, Sou🫀The Human Body: An Owner's GuideA free non-fiction mini-book for kids: explore the skeleton, muscles, heart, lungs, brain and digestion, and learn how y🧬The Human Genome and DNAA free non-fiction mini-book for ages 11-14: discover DNA, genes, chromosomes and the human genome — the secret code of 🏭The Industrial RevolutionA non-fiction history book for ages 10-13 on the Industrial Revolution: the steam engine, factories and machines, railwa🍄The Kingdom of FungiA free non-fiction book for ages 9-13: discover fungi, why they are not plants, how mushrooms grow, the hidden world of ⭐The Life of StarsA free online non-fiction book for ages 10-13: discover what stars really are, how they are born in vast clouds of gas, 🔬The Living CellA free non-fiction mini-book for ages 11-14: discover the cell, the tiny building block of all living things, and the bu🗿The Maya and the AztecsA non-fiction history book for ages 10-13 on the Maya and the Aztecs: great cities and pyramids, astronomy and calendars🏹The Mongol EmpireA free online non-fiction history book for ages 9-13 about the Mongol Empire: Genghis Khan, fearless horse warriors, the🕌The Ottoman EmpireA free online non-fiction history book for ages 9-13 about the Ottoman Empire: the rise of the Ottoman Turks, the fall o🌲The Secret Life of TreesA free non-fiction book for ages 9-13: how trees grow, make food from sunlight, defend themselves, talk through undergro🎬The Story of CinemaA free online non-fiction book for ages 10-13: discover how moving pictures were invented, why our eyes are fooled into 💻The Story of ComputersA free non-fiction mini-book on the history of computers: from the abacus and Babbage's engines to room-sized machines, ⚡The Story of ElectricityA free online non-fiction book for ages 11-14: discover what electricity is, how circuits and currents work, the scienti🦎The Story of EvolutionA free non-fiction mini-book for ages 11-14: discover how life on Earth changed over billions of years through natural s📖The Story of PrintingA free online non-fiction history book for ages 9-13 on the story of printing: from handwritten scrolls and woodblocks t🤖The Story of RobotsA free online non-fiction book for ages 10-13: discover what a robot really is, how robots sense, think and move, where 🧪The Story of the Periodic TableA free non-fiction mini-book for ages 11-14: discover atoms, elements and the brilliant pattern of the periodic table th🔭The Story of the TelescopeA free online non-fiction book for ages 10-13: discover how the telescope was invented, how lenses and mirrors gather li🎭The Story of TheatreA free online non-fiction book for ages 10-13: discover how theatre began in ancient times, how plays are made, the work🚂The Story of TransportA free online non-fiction history book for ages 9-13 on the story of transport: from walking and the wheel to ships, tra🔤The Story of Writing and the AlphabetA non-fiction book for ages 10-13 on the history of writing: from cave marks and cuneiform to hieroglyphs, the first alp🦠The Tiny World of MicrobesA free online non-fiction book for ages 11-14: explore the invisible world of bacteria, viruses, fungi and other microbe🏛️The Wonders of the Ancient WorldA free online non-fiction history book for ages 9-13: discover the Seven Wonders of the Ancient World, from the Great Py🦎The World of Reptiles and AmphibiansA free non-fiction book for ages 9-13: the differences between reptiles and amphibians, how snakes, lizards, turtles, fr🏞️The World's Great RiversA free non-fiction geography book for ages 10-13: discover the world's great rivers — the Nile, Amazon, Mississippi, Yan🌟Women Who Changed the WorldA free non-fiction mini-book about remarkable women in history: Marie Curie, Ada Lovelace, Rosa Parks, Wangari Maathai,
⚽ Deporte
💪Bodyweight Strength ExercisesLearn safe bodyweight strength exercises for young athletes: how muscles get stronger, correct form for squats, push-ups🏃♂️Building Stamina and EnduranceLearn how to build stamina and endurance: what aerobic fitness is, how the body adapts to cardio training, and a safe, b🧱Core Strength and StabilityDiscover what your core really is and why core strength matters for posture, power and injury prevention. Learn safe cor❤️Exercise and a Healthy HeartDiscover how exercise builds a healthy heart: how the heart works, what aerobic activity does to it, why a strong heart 🌡️Exercising Safely in Hot and Cold WeatherLearn how your body controls its temperature during exercise and how to stay safe in heat and cold: spotting warning sig🤺Fencing: The Sport of the SwordDiscover fencing: the three weapons (foil, epee and sabre), how points are scored, the safety equipment that makes it po🤸Flexibility and StretchingLearn about flexibility and stretching: what flexibility is, the difference between dynamic and static stretches, when t🫀How the Heart and Lungs Work During ExerciseLearn how your heart and lungs work during exercise: how oxygen reaches your muscles, why your heart beats faster, and h🎯How to Set Fitness GoalsLearn how to set fitness goals that actually work: use the SMART method, balance outcome and process goals, track progre💪How Your Body Grows Stronger With ExerciseDiscover how the body adapts to exercise: why muscles, heart, bones and lungs get stronger, the role of rest and food, a💪How Your Muscles WorkDiscover how your muscles work: how they contract to pull bones, why muscles work in pairs, what makes them stronger, an💧Hydration and ExerciseUnderstand hydration and exercise: why water matters, how sweating cools you, the signs of dehydration, when to use spor🏒Ice Hockey: The Fastest Team Sport on IceDiscover ice hockey: how the game works, the rules, the positions, the equipment that keeps players safe, and the skills🌈Moving to Feel Good and Reduce StressLearn how exercise boosts mood and reduces stress: the brain chemistry behind 'feeling good', how movement calms worry, 🚣Rowing: Power, Rhythm and Teamwork on the WaterLearn about rowing: how boats and oars work, the difference between sculling and sweep rowing, the role of the cox, the 🌍Sports Around the WorldTake a tour of sports around the world: from soccer and cricket to kabaddi, sumo, hurling, and sepak takraw. Learn how c🩹Basic Sports First Aid: The RICE MethodLearn basic sports first aid and the RICE method, Rest, Ice, Compression and Elevation, for treating sprains and strains🎾Squash: The Fast Game of the Four-Walled CourtDiscover squash: how this fast racket sport works, the rules, why you share one court and hit the same walls, the import🏄Surfing: Riding the Ocean's WavesLearn about surfing: how ocean waves form and break, the parts of a surfboard, the key skills of paddling and the pop-up🤝Teamwork and SportsmanshipLearn about teamwork and sportsmanship in sport: how to play your role on a team, communicate, win and lose gracefully, 🚣The Basics of RowingLearn how rowing works: sculling versus sweep, the four parts of the stroke, why teamwork and rhythm matter, the cox's j🏄The Basics of SurfingAn introduction to surfing: how waves work, paddling and the pop-up, surf etiquette and right of way, reading the ocean,🏅The Olympic GamesDiscover the Olympic Games: their ancient Greek origins, the modern revival, the meaning of the five rings, the Olympic 🦾The Paralympic GamesLearn about the Paralympic Games: their history, what they celebrate, how athletes are grouped by classification, the ra🤺The Rules of FencingDiscover the rules and skills of fencing: the three weapons (foil, epee and sabre), target areas, right of way, the on-g🏒The Rules of Ice HockeyA clear lesson on the rules and skills of ice hockey: how to score, the offside and icing rules, key positions, skating 🎾The Rules of SquashA beginner's guide to the rules and skills of squash: how to serve and score, the tin and out lines, sharing the court s🤽The Rules of Water PoloLearn the rules and skills of water polo: how to score in the pool, the key fouls, treading water with the eggbeater kic🤽Water Polo: Football and Swimming CombinedLearn about water polo: how this tough team sport works, the rules, the positions, the famous 'eggbeater' kick, and why 😴Why Sleep Matters for AthletesDiscover why sleep matters for athletes: how sleep repairs muscles, builds skills, releases growth hormone, sharpens rea
🤖 IA
♿AI and Accessibility: Helping EveryoneHow AI improves accessibility: screen readers, live captions, image descriptions, speech tools and navigation help for p🎨AI and Creativity: Can Machines Be Creative?A middle-school AI lesson on AI and creativity: how AI makes art, music and stories by remixing patterns, what real crea🚀AI and the Jobs of the FutureA friendly, balanced look for middle-schoolers at AI and future jobs: which work changes, which new jobs appear, and the🎨AI in Art and MusicHow AI makes art and music: learning patterns from examples, generating new pieces, and honest questions about copying, 🌍AI in Everyday LifeA grounded middle-school guide to AI in everyday life: where it really helps, how it works, its real limits and risks, a🚀AI in Space ExplorationA clear middle-grade guide to AI in space exploration: how rovers drive themselves, how AI sorts telescope data and plan⚽AI in SportsA clear middle-grade guide to AI in sports: how teams use data and machine learning to track players, scout talent, judg🌦️AI in Weather ForecastingHow AI helps forecast the weather: a middle-school guide to physics models, machine-learning forecasts like nowcasting, 🔀Classification vs PredictionUnderstand the two main jobs of supervised AI: classification sorts things into categories, regression predicts a number👁️Computer Vision and Face RecognitionHow computer vision and face recognition work: from pixels to features to matching faces, plus real limits, errors, bias🌳Decision Trees ExplainedA clear guide to decision trees in machine learning: how a model learns yes/no questions to sort data, why they are easy📋Expert Systems and RulesDiscover expert systems: older AI that uses hand-written if-then rules to make decisions like a specialist. See how they🩺How AI Helps DoctorsA middle-school lesson on how AI supports doctors: reading medical scans, sorting records, predicting risk and speeding 🎙️How AI Recognizes SpeechHow AI recognizes speech, step by step: from sound waves to digital numbers, to phonemes and words, plus why it mishears🎯How Recommendation Systems WorkA middle-school guide to recommendation systems: how YouTube, Netflix and Spotify suggest content using collaborative fi🔎How Search Engines WorkA clear middle-school lesson on how search engines work: crawling, indexing, ranking with signals, and how AI shapes res📧How Spam Filters WorkHow email spam filters work: a middle-school guide to the rules, machine learning and probability that sort junk mail fr📝How to Write Good PromptsLearn prompt basics for AI chatbots: give a role, context, a clear task, examples and a format. See concrete before-and-🌍How Translation Apps WorkHow translation apps work: from old word-by-word systems to neural machine translation that learns from millions of exam🤝Making AI Fair for EveryoneA clear middle-school lesson on making AI fair: why AI can be unfair, how biased data causes it, real examples, and what🧠Neural Networks ExplainedA middle-school guide to neural networks: neurons, weights, layers, activation, and how training with backpropagation le🏷️Supervised vs Unsupervised LearningA clear guide to supervised vs unsupervised learning: how labelled examples train a model to predict, how unlabelled dat🎯Training, Testing and AccuracyLearn how AI is built: how a model trains on examples, why it must be tested on data it never saw, and what accuracy rea🧩What Are Tokens in AI?Understand tokens: the chunks of text an AI reads and writes. Learn how words split into tokens, why context windows and⚙️What Is Machine Learning?A middle-school guide to machine learning: training data, features, models, neural networks, supervised vs unsupervised
💻 Programación
📡Broadcasting Messages in ScratchA step-by-step middle-school lesson on broadcasts in Scratch: how 'broadcast' and 'when I receive' let sprites talk to e🧮Building a Calculator in PythonBuild a working calculator in Python step by step: read numbers with input, do the four operations, handle the divide-by🎨Building a Drawing App in ScratchA step-by-step middle-school lesson on building a drawing app in Scratch with the pen: draw with the mouse, lift the pen🧺Catch the Falling Objects Game in ScratchA step-by-step middle-school lesson on building a catch-the-falling-objects game in Scratch: a basket you move, apples t👯Cloning Sprites in ScratchA step-by-step middle-school lesson on clones in Scratch: how 'create clone', 'when I start as a clone', and 'delete thi🧩Creating Custom Blocks in ScratchA middle-school Scratch coding lesson on custom blocks: learn to make your own blocks with My Blocks, add inputs, avoid 🎨CSS Colours and FontsA friendly middle-school lesson on CSS colours and fonts: set text and background colours with names, hex and rgb, choos🎲Build a Dice Roller in PythonCode a virtual dice roller in Python. Roll one die or many, choose how many sides, add up the total and show ASCII dice 🧩Functions: Reusable Blocks of CodeA middle-school coding lesson on functions: learn how to define and call functions, pass arguments, return values, and w↩️Functions That Return ValuesUnderstand how Python functions return values: the difference between return and print, capturing results in variables, ⚽Gravity and Bouncing Physics in ScratchA step-by-step middle-school lesson on simple physics in Scratch: make a ball fall with gravity using a velocity variabl🔢How Computers Store Data (Binary)Discover how computers store everything as binary: bits and bytes, why machines use only 0s and 1s, how numbers, letters🖼️How Images Are Stored: Pixels and ColourDiscover how computers store images as a grid of pixels, how RGB colour and hex codes work, what resolution and bit dept🔊How Sound Is Stored DigitallyLearn how computers turn sound into numbers using sampling, sample rate and bit depth, why CD audio uses 44,100 samples 🧠How the CPU WorksMeet the CPU, the brain of the computer: learn the fetch-decode-execute cycle, what registers and the clock do, how bill🌐How the Internet WorksHow the internet works explained simply: IP addresses, packets, servers and clients, DNS, and what happens when you open📝HTML Forms and InputsA clear, hands-on lesson on HTML forms and inputs for middle-school coders: build a form with text boxes, email fields, 🏷️Introduction to HTML TagsA beginner-friendly introduction to HTML tags: headings, paragraphs, links, images, lists and the page skeleton. Learn h📋Lists and ArraysLearn what lists and arrays are: how computers store many values in one place, how to add, read, and change items by the🗂️Loading Data into Python with Lists and DictionariesGet real data into Python: build it as lists, dictionaries and lists-of-dicts, then loop, filter, count and summarise it🔁Loops: Making the Computer RepeatA middle-school coding lesson on loops: learn what loops are, how for and while loops work, why they save time, and see 📝Build a Mad Libs Game in PythonCode a funny Mad Libs word game in Python. Collect nouns, verbs and adjectives with input, slot them into a story with f🎮Making a Platformer in ScratchA step-by-step middle-school lesson on building a platformer in Scratch: left and right movement, gravity, jumping with 🏓Making a Pong Game in ScratchA step-by-step middle-school lesson on building Pong in Scratch: a bouncing ball, a paddle you control with the mouse, b🔳Nested Loops and PatternsA middle-school coding lesson on nested loops: learn how a loop inside a loop works, why the inner loop runs fully for e🔢Build a Number Guessing Game in PythonCode a complete number guessing game in Python: the computer picks a secret number, you guess, and it gives higher/lower⚖️Python Comparison and LogicLearn Python comparison and logic: ==, !=, <, >, the True and False booleans, and the and, or, not operators. Build cond🔁Python For LoopsLearn Python for loops: loop over lists and strings, use range() to count, build running totals with an accumulator, and🔀Python: if, elif, elseMaster Python decisions with if, elif and else: comparison operators, branching, why elif beats stacked ifs, chained con⌨️Python Input and OutputLearn Python input and output: print() with sep and end, reading text with input(), converting strings to numbers with i📋Python Lists in DepthGo deeper with Python lists: indexing, slicing, append, insert, remove, sort and reverse, len, and looping with for. Mas🔁Python Loops and ListsCombine Python loops and lists: use a for loop to visit every item, build lists, count and total values, and use range()🔢Python Numbers and MathLearn Python numbers and math: integers, floats, the arithmetic operators, floor division, modulo, exponents, operator o🔁Python While LoopsMaster Python while loops: how a condition controls repetition, updating the loop variable, avoiding infinite loops, bre🎲Random Numbers and Games in PythonMake Python games unpredictable with the random module: use randint, choice, shuffle and random to roll dice, pick cards✊Build Rock Paper Scissors in PythonCode the classic Rock Paper Scissors game in Python against the computer. Learn input, random.choice, comparing strings 🖥️What Is an Operating System?What is an operating system? Learn how the OS manages the CPU, memory, files, and devices, what a kernel does, and examp✍️Working with Text and StringsLearn how to work with text and strings in Python: create strings, join them, slice them, change case, find and replace,🧹Writing Clean Code and CommentsLearn to write clean Python code: clear variable names, helpful comments and docstrings, avoiding repetition with functi