Understanding Teens

Kit has a box of ten eggs. She has 3 eggs too! How many eggs in all?

1st Grade Math

Step 1: Count the Ones

The box is 1 ten. Count the ones out of the box.

3 ones are out of the box. So Kit has 1 ten and 3 ones.

10 + 3 = ?

Add the ten and the 3 ones. Count on from ten!

10 + 3 = 13. Count on from ten: 11, 12, 13. Kit has 13 eggs!

Teen Numbers

          A teen number is 1 ten and some ones.

          11 = 10 + 1

          13 = 10 + 3

          19 = 10 + 9

See the ten first. Then just add the ones!

1 ten and 5 ones. How many in all?

10 + 5 = 15. 1 ten and 5 ones make 15.

10 + 7 = ?

10 + 7 = 17. Count on from ten: 11, 12, 13, 14, 15, 16, 17.

10 + ? = 14

14 is 1 ten and how many ones?

10 + 4 = 14. 14 is 1 ten and 4 ones.

Sam has ten rocks in a box. He gets 6 rocks. How many in all?

10 + 6 = 16. 1 ten and 6 ones make 16 rocks.

18 is 1 ten and how many ones?

18 = 10 + 8. That is 1 ten and 8 ones.

19 = ?

What is the same as 19?

19 = 10 + 9. That is 1 ten and 9 ones. It is the big teen!

Can you find a group of ten at your home? What can you add to it?

Great Work!

0/8

correct

add ten ones count on