Lesson 3.2 · Counting to 100
Teen numbers: ten and some more
Numbers from 11 to 19 are called teen numbers. Each one has a secret inside: it is ten and some more.
Ten and some more
Look at 13 with dots. Put ten in one row. Put the rest in the next row.
🔵 🔵 🔵 🔵 🔵 🔵 🔵 🔵 🔵 🔵
🔵 🔵 🔵
That is 10 and 3 more. Ten and three make thirteen.
Teen numbers
Every teen number is 10 ones and some more ones.
- 11 is 10 and 1 more.
- 15 is 10 and 5 more.
- 19 is 10 and 9 more.
Read the number
Look at the digits in a teen number. The 1 stands for the ten. The other digit tells how many more.
In 17, the 1 means ten. The 7 means 7 more. So 17 is 10 and 7.
Worked example: How many more?
14 is 10 and how many more?
🟢 🟢 🟢 🟢 🟢 🟢 🟢 🟢 🟢 🟢
🟢 🟢 🟢 🟢
The top row has 10. The bottom row has 4. So 14 is 10 and 4 more.
Worked example: Name the number
What number is 10 and 6 more?
🍓 🍓 🍓 🍓 🍓 🍓 🍓 🍓 🍓 🍓
🍓 🍓 🍓 🍓 🍓 🍓
Start at ten. Count 6 more: eleven, twelve, thirteen, fourteen, fifteen, sixteen. It is 16.
Worked example: Just 10
What number is 10 and 0 more?
Ten and nothing more is just 10. The 0 in 10 means "no extra ones."
Common mistake
The 1 in a teen number means ten, not one. In 12 there are 12 things, not 1 and 2.
Practice
12 is 10 and how many more?
Type a number.
How many dots are in the bottom row?
🔴 🔴 🔴 🔴 🔴 🔴 🔴 🔴 🔴 🔴
🔴 🔴 🔴 🔴 🔴
So the number is 10 and how many more?
Type a number.
What number is 10 and 8 more?
Type a number.
How many cats?
🐱 🐱 🐱 🐱 🐱 🐱 🐱 🐱 🐱 🐱
🐱 🐱 🐱
Type a number.
Which shows 17?
19 is 10 and how many more?
Type a number.
Mia has a full row of 10 buttons and 1 more button. How many buttons does she have?