122 Speed Math for Kids
methods of carrying and borrowing. Use the method you are familiar
with or that you fi nd easier.
Subtraction method one
Here is a typical subtraction:
8 2 6 5
- 3 8 9 7
4 3 6 8
Th is is how the solution might look:
7 1 5
8 2 6 5 - 3 8 9 7
4 3 6 8
Let’s see how easy subtraction works. Subtract 7 from 5. You can’t,
so you “borrow” 1 from the tens column. Cross out the 6 and write
- Now, here is the diff erence. You don’t say 7 from 15, you say 7
from 10 equals 3, then add the number above (5) to get 8, the fi rst
digit of the answer.
With this method, you never subtract from any number higher than - Th e rest is addition.
Nine from 5 won’t go, so borrow again. Nine from 10 is 1, plus 5 is
6, the next digit of the answer.
Eight from 1 won’t go, so borrow again. Eight from 10 is 2, plus 1
is 3, the next digit of the answer.
Th ree from 7 is 4, the fi nal digit of the answer.
Subtraction method two
8 12 16 15
- 13 18 1 9 7
4 3 6 8