10 printable sets · answer key on every set

Fact Families: Add and Subtract Worksheets

CCSS 1.OA.B.3
20 problems per set
Answer key included

What this skill is

Seeing that 3, 5, and 8 make four related facts: 3+5=8, 5+3=8, 8−3=5, 8−5=3.

When it comes up: Middle of first grade.

The mistake to watch for

Writing the two additions correctly, then writing 3 − 5 and 5 − 8 for the subtractions — the largest number must start the subtraction.

How to help

Say the whole and the parts out loud before writing. The whole always comes first when taking away.

Next: Place value: tens and ones.

A worked example

The numbers 2, 5 and 7 make a fact family: 2 + 5 = 7, 5 + 2 = 7, 7 − 2 = 5, 7 − 5 = 2. The biggest number is the total, so it comes first in the subtraction facts.

Words to know

family: A group of numbers that go together, like 3, 4 and 7 in a fact family.
sum: The answer you get when you add.
difference: The answer you get when you subtract.
add: To put numbers together to find how many in all.
subtract: To take one number away from another to find how many are left.

Practice

Write the four facts for each number family.

Showing Set 1 · 20 problems

3, 4, 7 → write 4 facts
9, 3, 12 → write 4 facts
2, 4, 6 → write 4 facts
6, 2, 8 → write 4 facts
9, 5, 14 → write 4 facts
7, 9, 16 → write 4 facts
3, 5, 8 → write 4 facts
9, 9, 18 → write 4 facts
8, 6, 14 → write 4 facts
6, 6, 12 → write 4 facts
6, 3, 9 → write 4 facts
8, 8, 16 → write 4 facts
9, 6, 15 → write 4 facts
6, 7, 13 → write 4 facts
8, 7, 15 → write 4 facts
5, 9, 14 → write 4 facts
2, 6, 8 → write 4 facts
6, 4, 10 → write 4 facts
3, 9, 12 → write 4 facts
4, 3, 7 → write 4 facts

Download this set20 problems · answer key included PDF

Answer key

3+4=7; 4+3=7; 7−3=4; 7−4=3
9+3=12; 3+9=12; 12−9=3; 12−3=9
2+4=6; 4+2=6; 6−2=4; 6−4=2
6+2=8; 2+6=8; 8−6=2; 8−2=6
9+5=14; 5+9=14; 14−9=5; 14−5=9
7+9=16; 9+7=16; 16−7=9; 16−9=7
3+5=8; 5+3=8; 8−3=5; 8−5=3
9+9=18; 9+9=18; 18−9=9; 18−9=9
8+6=14; 6+8=14; 14−8=6; 14−6=8
6+6=12; 6+6=12; 12−6=6; 12−6=6
6+3=9; 3+6=9; 9−6=3; 9−3=6
8+8=16; 8+8=16; 16−8=8; 16−8=8
9+6=15; 6+9=15; 15−9=6; 15−6=9
6+7=13; 7+6=13; 13−6=7; 13−7=6
8+7=15; 7+8=15; 15−8=7; 15−7=8
5+9=14; 9+5=14; 14−5=9; 14−9=5
2+6=8; 6+2=8; 8−2=6; 8−6=2
6+4=10; 4+6=10; 10−6=4; 10−4=6
3+9=12; 9+3=12; 12−3=9; 12−9=3
4+3=7; 3+4=7; 7−4=3; 7−3=4

All 10 sets

Each set is a different list of 20 problems with its own answer key. Use the buttons above to look at one on this page, or download any of them as a PDF.

How these sheets were made

Problems are generated for each set and checked against 1.OA.B.3 before the sheet is built — no duplicates, and every problem falls inside the standard's number range.