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🔢 Kindergarten • 🔟 Counting to 20

Counting to 20 — Numbers Beyond 10

📖 Lesson Kindergarten Last updated: March 2026

You learned to count to 10 — amazing! Now it's time to go further. The numbers 11 to 20 are called "teen numbers," and they all have something special in common: they're 10 plus some more!

The Teen Numbers: 11 to 19

The teen numbers might sound tricky, but they follow a pattern:

11 — eleven (10 + 1 more) 12 — twelve (10 + 2 more) 13 — thirteen (10 + 3 more) 14 — fourteen (10 + 4 more) 15 — fifteen (10 + 5 more) 16 — sixteen (10 + 6 more) 17 — seventeen (10 + 7 more) 18 — eighteen (10 + 8 more) 19 — nineteen (10 + 9 more)

See the pattern? Every teen number is just 10 plus a number you already know!

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Example 13 = 10 + 3 → think of it as one full group of ten, plus three extra ones.
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Tip Use a ten frame! Fill up 10 spaces, then count the extras. This builds place value understanding.

The Special Number: 20

20 is special because it's 2 groups of 10! If you fill up two ten-frames, you have exactly 20.

20 = 10 + 10

Twenty is the gateway to even bigger numbers. Once you can count to 20, you're ready for the big leagues!

Practice Counting to 20

Let's count all the way: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20! 🎉

Now try counting 20 objects. Line up 20 crayons, 20 blocks, or 20 cereal pieces and count each one. Remember to touch each one as you count!

📝 Key Vocabulary

Teen numbers
The numbers from 13 to 19 — they all have "teen" in their name
Ten frame
A rectangle with 10 boxes used to show numbers up to 10 (or 20 with two frames)

📐 Standards Alignment

K.CC.A.1 CCSS.MATH

Count to 100 by ones and by tens.

K.CC.B.4 CCSS.MATH

Understand the relationship between numbers and quantities.

K.NBT.A.1 CCSS.MATH

Compose and decompose numbers from 11 to 19 into ten ones and some further ones.

🔗 Glossary Connections

⚠️ Common Mistakes to Watch For

  • Mixing up 12 and 20, or 13 and 30 — practice writing these numbers side by side
  • Losing track in the teens — counting songs help!
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Real-World Connection Many things come in groups of 20: fingers and toes together make 20! A score in sports is a way of counting too.
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Fun Fact! The word "twenty" comes from an Old English word meaning "two tens." Even the name tells you it's 10 + 10!