Teen Numbers 11 to 19

Numbers in their teens

After you count past 10, you reach the teen numbers: 11, 12, 13, 14, 15, 16, 17, 18, 19.

Here is the big secret that makes them easy: every teen number is one ten and some extra ones. Once you know that, teen numbers stop being tricky.

A ten and some ones

Think of a full bundle of ten sticks held together with a band. That bundle is your "ten". Now lay some single sticks next to it. Those single sticks are the "ones".

• 1 ten and 3 ones = 13 (we say thirteen).
• 1 ten and 7 ones = 17 (we say seventeen).
• 1 ten and 0 ones = 10 — just the ten, with no extra ones.

Every teen number has one ten. Only the number of ones changes. You can learn more about this idea in our lesson on place value with tens and ones.

Use a ten frame

A ten frame is a box with 10 spaces — two rows of five. When you fill it completely, you have made a ten.

To show a teen number, fill the ten frame, then put the extra counters outside it:

⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫ ⚫

The full frame is 10. The three counters beside it are the extra ones. Together they make 13. Seeing the full ten plus the extras helps the number make sense.

Why the names are tricky

The names of teen numbers can be confusing, and it is not your fault!

• Eleven and twelve sound nothing like "ten and one" or "ten and two". You just have to learn these two.
• Thirteen to nineteen say the ones first: "four-teen" is 4 and ten, but we write the ten first as 14.

A great trick is to say each number as "ten and...":

We write	We say	Think	Tens and ones
11	eleven	ten and 1	1 ten, 1 one
12	twelve	ten and 2	1 ten, 2 ones
13	thirteen	ten and 3	1 ten, 3 ones
15	fifteen	ten and 5	1 ten, 5 ones
18	eighteen	ten and 8	1 ten, 8 ones

Worked example 1: building a number

Build 16 with a ten frame and counters.

First fill the ten frame: that is 10. Then add 6 more counters beside it. Ten and six more makes 16. Easy when you start with the ten!

Worked example 2: reading a number

You see this written: 14. What does it mean?

The 1 stands for 1 ten. The 4 stands for 4 ones. So 14 is ten and four more. If you count counters, you would have 10 in the frame and 4 outside.

Worked example 3: one more in the teens

What is one more than 13? Start at 13 and count on one: 14. Notice the ten stays the same — you only added one more one. This is just like our one more and one less lesson, but in the teens.

Why teen numbers matter

Teen numbers are your first taste of place value — the idea that where a digit sits tells you what it is worth. In 13, the 1 is worth a whole ten, not just one. Understanding this now makes counting to 20, 50 and 100 much easier later.

Try it yourself

Play Build a Teen. You need a ten frame (or just draw a box with 10 spaces) and at least 19 small objects.

1. Pick a teen number card, say 15.
2. Fill the ten frame completely. Say: "That's ten!"
3. Add the extra ones beside it. Say: "Ten and five more..."
4. Say the whole number: "...is fifteen!"
5. Challenge: Cover the full ten frame with a cloth. Can you remember it is 10, and just count on the extra ones to name the number?

Do this for several teen numbers and the names will start to feel natural.

What's next?

Once teen numbers feel comfortable, keep counting upward. Move on to counting to 20 to put all these numbers in order.