MyMathKidK-8 Curriculum

Grade 1 Subtraction: Subtraction Within 20

Master subtraction with minuends up to 20

What You'll Learn

Subtract any single-digit number from numbers up to 20
Use multiple strategies (counting back, making 10, think addition)
Build fluency with all basic subtraction facts

📖All the Way to 20

You can now subtract from numbers as high as 20! This includes 16, 17, 18, 19, and 20.

📖Think Addition

For 17 - 8, think: 8 + ? = 17. If you know 8 + 9 = 17, then 17 - 8 = 9!

📖Choose Your Strategy

You now know many ways to subtract: counting back, making 10, thinking addition. Use whichever works best for you!

💡

If you are stuck, try a different strategy. There is always more than one way to solve a problem!

Worked examples

Real problems from the practice worksheets, solved one step at a time.

Example 1
15 − 4 = ?
1. Start at 15 on the number line.
2. Count backward 4 steps.
3. You land on 11.
4. Or think: 4 + ? = 15. The answer is 11!
Answer: 11
Example 2
13 − 8 = ?
1. Start at 13 on the number line.
2. Count backward 8 steps.
3. You land on 5.
4. Or think: 8 + ? = 13. The answer is 5!
Answer: 5
Example 3
19 − 6 = ?
1. Start at 19 on the number line.
2. Count backward 6 steps.
3. You land on 13.
4. Or think: 6 + ? = 19. The answer is 13!
Answer: 13

Practice Worksheets

Subtraction Within 20 (Set A)

Practice all subtraction facts within 20

Subtraction Within 20 (Set B)

More practice subtracting within 20

Subtraction Within 20 (Set C)

Additional drill within 20

Subtraction Within 20 (Set D)

Keep practicing subtraction within 20

Subtraction Within 20 (Set E)

More practice within 20

Subtraction Within 20 (Set F)

Master subtraction within 20

Subtraction Within 15