Grade: Grade 1 Subject: Mathematics Unit: Addition & Subtraction Within 20 SAT: Algebra ACT: Math

Subtraction Facts

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What is Subtraction?

Subtraction means taking away or finding the difference between two numbers. When we subtract, we use the minus sign (-) and the equals sign (=).

When we subtract one number from another, we find the difference. The difference is the answer to a subtraction problem.

Subtraction Words to Know

  • Minus (-) - This sign means "take away" or "subtract"
  • Equals (=) - This sign means "the same as"
  • Difference - The answer when you subtract numbers

Ways to Subtract

There are many ways to subtract numbers!

  • Count back - Start with the bigger number and count backward
  • Use objects - Put out objects, take some away, count what is left
  • Draw pictures - Draw circles, cross some out, count the rest
  • Think addition - Ask "what plus ? equals the bigger number?"

Count Back Trick

To subtract 7 - 3, start with 7 in your head. Then count back 3: "7... 6, 5, 4!" The answer is 4!

Examples

Let's work through these subtraction problems together!

Example 1: 5 - 2 = ?

Lily has 5 cookies. She eats 2 cookies. How many cookies are left?

Step 1: Draw 5 cookies: OOOOO

Step 2: Cross out 2 cookies: OOOOO

Step 3: Count what is left: 1, 2, 3

Answer: 5 - 2 = 3

Example 2: 8 - 3 = ?

There are 8 balloons. 3 balloons pop. How many balloons are left?

Step 1: Start with 8

Step 2: Count back 3: 7, 6, 5

Answer: 8 - 3 = 5

Example 3: 10 - 4 = ?

Ben has 10 grapes. He gives 4 to his sister. How many grapes does Ben have left?

Step 1: Start with 10

Step 2: Count back 4: 9, 8, 7, 6

Answer: 10 - 4 = 6

Example 4: 12 - 5 = ?

There are 12 birds on a fence. 5 birds fly away. How many birds are still on the fence?

Step 1: Start with 12

Step 2: Count back 5: 11, 10, 9, 8, 7

Answer: 12 - 5 = 7

Example 5: 15 - 8 = ?

Sara has 15 stickers. She uses 8 stickers on her art project. How many stickers does she have left?

Step 1: Think: 8 + ? = 15

Step 2: 8 + 7 = 15, so 15 - 8 = 7

Answer: 15 - 8 = 7

Practice Problems

Try these subtraction problems on your own! Use counting back or draw pictures to help.

1. 6 - 2 = ?

Show Answer

6 - 2 = 4. Start with 6 and count back 2: 5, 4!

2. 7 - 4 = ?

Show Answer

7 - 4 = 3. Start with 7 and count back 4: 6, 5, 4, 3!

3. 9 - 3 = ?

Show Answer

9 - 3 = 6. Start with 9 and count back 3: 8, 7, 6!

4. 10 - 5 = ?

Show Answer

10 - 5 = 5. Half of 10 is 5!

5. 8 - 8 = ?

Show Answer

8 - 8 = 0. When you take away all of something, you have zero left!

6. 11 - 4 = ?

Show Answer

11 - 4 = 7. Start with 11 and count back 4: 10, 9, 8, 7!

7. 13 - 6 = ?

Show Answer

13 - 6 = 7. Think: 6 + 7 = 13, so 13 - 6 = 7!

8. 14 - 7 = ?

Show Answer

14 - 7 = 7. This is a doubles fact! 7 + 7 = 14.

9. 16 - 9 = ?

Show Answer

16 - 9 = 7. Think: 9 + 7 = 16!

10. 18 - 9 = ?

Show Answer

18 - 9 = 9. This is a doubles fact! 9 + 9 = 18.

Check Your Understanding

Answer these questions to see what you learned!

1. What does the - sign mean?

Show Answer

The - sign means take away or subtract.

2. What do we call the answer to a subtraction problem?

Show Answer

The answer to a subtraction problem is called the difference.

3. Maria has 9 pencils. She gives 4 pencils to her friend. How many pencils does Maria have left?

Show Answer

9 - 4 = 5 pencils. Maria has 5 pencils left!

4. What is 20 - 10?

Show Answer

20 - 10 = 10. Half of 20 is 10!

Next Steps

  • Practice subtraction at home - count things and take some away
  • Try using addition to help you subtract faster
  • Go back to Addition Facts if you need to review
  • You have learned so much about adding and subtracting!