Subtraction Shortcuts and Tips

1
Subtraction Shortcutsand Tips

• By Mark Driskill

2
Subtracting Across Zeros

• 3 0 2
• 1 9 8

3
Step 1 Borrow 1 from the 30

• 3 0 2
• 1 9 8

4
Step 2 Cross out the 30

• 3 0 2
• 1 9 8

5
Step 3 Write a 29 above the 30
2 9

• 3 0 2
• 1 9 8

6
Step 4 Write a 1 in front of the 2
2 9
1

• 3 0 2
• 1 9 8

7
Step 5 Subtract 8 from 12
2 9
1

• 3 0 2
• 1 9 8

4
8
Step 6 Subtract 9 from 9
2 9
1

• 3 0 2
• 1 9 8

4
0
9
Step 7 Subtract 1 from 2
2 9
1

• 3 0 2
• 1 9 8

4
0
1
10
Were Finished
2 9
1

• 3 0 2
• 1 9 8

4
0
1
11
Second Example

• 8 0 0 2
• 3 7 6 5

12
Step 1 Borrow 1 from 800

• 8 0 0 2
• 3 7 6 5

13
Step 2 Cross out the 800

• 8 0 0 2
• 3 7 6 5

14
Step 3 Write 799 above the 800
7 9 9

• 8 0 0 2
• 3 7 6 5

15
Step 4 Write a 1 next to the 2
7 9 9
1

• 8 0 0 2
• 3 7 6 5

16
Step 5 Subtract 5 from the 12
7 9 9
1

• 8 0 0 2
• 3 7 6 5

7
17
Step 6 Subtract 6 from the 9
7 9 9
1

• 8 0 0 2
• 3 7 6 5

7
3
18
Step 7 Subtract 7 from the 9
7 9 9
1

• 8 0 0 2
• 3 7 6 5

7
3
2
19
Step 7 Subtract 3 from the 7
7 9 9
1

• 8 0 0 2
• 3 7 6 5

7
3
2
4
20
Were Finished
7 9 9
1

• 8 0 0 2
• 3 7 6 5

7
3
2
4
21
Its Your Turn Blackhawks
6 9 9
1

• 7 0 0 5
• 2 8 3 6

9
6
1
4
22
Its Your Turn Again BLACKHAWKS
8 9 9
1

• 9 0 0 4
• 7 9 5 6

8
4
0
1
23
Subtraction Tips
24
Never subtract the top number from the bottom
number

• 6 1 3
• 2 7 9

4 6 6
Your answer will always be wrong.
25
Never borrow unless you need to
5

• 9 6 2
• 8 4 1

1
Your answer will always be wrong.
26
Practice your subtraction facts
9
13

• 18 9
• 18 7
• 16 8
• 14 8
• 12 9
• 11 3
• 15 7
• 9 3

• 18 5
• 18 3
• 16 7
• 14 6
• 12 4
• 11 7
• 15 6
• 9 5

11
15
8
9
6
8
3
8
8
4
8
9
6
4