K–2 Math · Lesson 2 of 8
Lesson 2: Counting to 20
Let's practice counting from 1 all the way to 20! Counting helps us know how many things we have.
Key Concepts
Count One at a Time
When we count, we say one number for each object. Never skip one or count one twice! Touch each object as you count it.
Teen Numbers
The numbers 11 through 19 are called teen numbers. They all start with a 1 in the tens place — 11, 12, 13... all the way to 19!
Then Comes 20!
After 19 comes 20. Twenty means two groups of ten. Once you can count to 20, you can count almost anything!
🆕 Activity: Number Line
Click the numbers in order from 1 to 20. They will light up green when you get them right!
✅ Check Your Understanding
1. What number comes after 9?
2. How many teen numbers are there?
3. What comes after 19?