Introduction: Two-Digit Numbers

Do you recognize these numbers?

These numbers are the numerals 0-9. They each only have 1 digit. A digit is just a symbol that’s used to write a number.

What happens when you count above 9? Do you notice anything different?

Numbers from 10 to 99 are two-digit numbers. They have two numerals side-by-side! You can add a two-digit number to a one-digit number.

In this lesson, you will learn how to use a number line to add a two-digit number to a one-digit number.