# Subtraction Shortcuts

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```					Subtraction Shortcuts
and Tips

By Monica Yuskaitis
Subtracting Across Zeros

302
198
Step 1 – Borrow 1 from the 30

302
198
Step 2 – Cross out the 30

302
198
Step 3 – Write a 29 above the 30
2 9

302
198
Step 4 – Write a 1 in front of the 2
2 9

3 0 12
198
Step 5 – Subtract 8 from 12
2 9

3 0 12
198
4
Step 6 – Subtract 9 from 9
2 9

3 0 12
198
04
Step 7 – Subtract 1 from 2
2 9

3 0 12
198
104
We’re Finished
2 9

3 0 12
198
104
Second Example

8002
3765
Step 1 – Borrow 1 from 800

8002
3765
Step 2 – Cross out the 800

8002
3765
Step 3 – Write 799 above the 800
7 9 9
8002
3765
Step 4 – Write a 1 next to the 2
7 9 9
8 0 0 12
3765
Step 5 – Subtract 5 from the 12
7 9 9
8 0 0 12
3765
7
Step 6 – Subtract 6 from the 9
7 9 9
8 0 0 12
3765
37
Step 7 – Subtract 6 from the 9
7 9 9
8 0 0 12
3765
2 37
Step 7 – Subtract 3 from the 7
7 9 9
8 0 0 12
3765
4 2 37
We’re Finished
7 9 9
8 0 0 12
3765
4 2 37
6 9 9
7 0 0 15
2836
4 1 69
8 9 9
9 0 0 14
7956
1 0 48
Subtraction Tips
Never subtract the top number
from the bottom number
613
279
466
Never borrow unless you need to
5
9 6 12
841
18 –9= 9       18 – 5 = 13
18 – 7 = 11    18 – 3 = 15
16 – 8 = 8     16 – 7 =  9
14 – 8 = 6     14 – 6 =  8
12 – 9 = 3     12 – 4 = 8
11 – 3 = 8     11 – 7 = 4
15 – 7 = 8     15 – 6 = 9
9 – 3 =  6     9 – 5 =   4

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