What is subtraction?
Subtraction means taking away from a group to find how many are left. It shows how numbers become smaller.
- 5 − 2 = 3
- 10 − 4 = 6
- 8 − 1 = 7
The answer to a subtraction problem is called the difference.
Understanding subtraction with objects
Subtraction can be shown using objects, pictures, or drawings. You start with a group and take some away.
- You have 6 apples. You eat 2 apples. Now you have 4 apples.
- There are 9 balloons. 3 balloons pop. 6 balloons are left.
Using pictures or objects can help you understand subtraction more easily.
Subtraction facts up to 20
Subtraction facts up to 20 are subtraction problems where the starting number is 20 or less.
- 15 − 5 = 10
- 20 − 7 = 13
- 12 − 6 = 6
Learning subtraction facts helps you solve problems faster.
Using a number line to subtract
A number line shows numbers in order. To subtract, start at the first number and move backward.
- To solve 10 − 3, start at 10 and move back 3 steps to land on 7.
- To solve 14 − 5, start at 14 and move back 5 steps to reach 9.
Counting backward helps you find the correct answer.
Checking subtraction answers
You can check subtraction by adding the difference to the number that was taken away.
- 8 − 3 = 5, and 5 + 3 = 8
- 16 − 6 = 10, and 10 + 6 = 16
Addition and subtraction are related math skills.
Common Core alignment: CCSS.MATH.CONTENT.1.OA.C.6 – Add and subtract within 20.
Notes for teachers
This lesson is aligned with CCSS.MATH.CONTENT.1.OA.C.6. Use it for whole-class instruction, small-group practice, or independent work.
All content is 100% free, student-safe, and appropriate for classroom and home use.