Subtract 1: Subtraction Facts

The pattern in the answers

The answers 1 to 12 count up in order while the starting numbers 2 to 13 count up with them.

Tip for the subtract 1 facts

Say the number that comes just before it: for 13 - 1, the number before 13 is 12.

The 3 hardest facts

• 10 − 1 = 9 (matching addition: 1 + 9 = 10)
• 11 − 1 = 10 (matching addition: 1 + 10 = 11)
• 13 − 1 = 12 (matching addition: 1 + 12 = 13)

Starting numbers that cross a tens boundary, like 10 - 1 and 11 - 1, are the usual slip. Say the counting sequence backward from 11.

Check with addition

Every subtraction fact is an addition fact turned around. Add the answer back to 1 to get the number you started with.

• 1 + 1 = 2, so 2 − 1 = 1
• 2 + 1 = 3, so 3 − 1 = 2
• 3 + 1 = 4, so 4 − 1 = 3
• 4 + 1 = 5, so 5 − 1 = 4
• 5 + 1 = 6, so 6 − 1 = 5
• 6 + 1 = 7, so 7 − 1 = 6
• 7 + 1 = 8, so 8 − 1 = 7
• 8 + 1 = 9, so 9 − 1 = 8
• 9 + 1 = 10, so 10 − 1 = 9
• 10 + 1 = 11, so 11 − 1 = 10
• 11 + 1 = 12, so 12 − 1 = 11
• 12 + 1 = 13, so 13 − 1 = 12

Printable subtract 1 chart

One US Letter page, clear in black and white.

Questions parents ask