Same-Change Rule Subtraction Method

• If you add the same number to both numbers being subtracted, the answer is the same.

• If you subtract the same number from both numbers being subtracted, the answer is the same.

• Add or a subtract a number that will make the bottom number a multiple of ten.

Example: 59 – 34 =

Add the same number

Add 6:

	5	9	(add 6)		6	5
-	3	4	(add 6)	-	4	0
	2	5			2	5

Subtract the same number

Subtract 4:

	5	9	(subtract 4)		5	5
-	3	4	(subtract 4)	-	3	0
	2	5			2	5

Tip: This is a good method when you are trying to subtract numbers in your head.