Fact Families (Addition & Subtraction to 20) — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. 7 + 6 = 13
Use the doubles-plus-one trick: 6 + 6 is 12, so 7 + 6 is one more, which is 13. This begins the 6, 7, 13 fact family.
2. 6 + 7 = 13
Swapping the order of 7 and 6 still gives 13 because the parts stay the same. This turn-around fact belongs to the same fact family.
3. 13 - 7 = 6
Start at 13 and count back 7 to land on 6, the missing part. Subtraction undoes 6 + 7, leaving the other addend.
4. 13 - 6 = 7
Take the 6 part out of the whole 13, and 7 is what remains. This is the fourth and final fact in the 6, 7, 13 family.
5. 9 + 5 = 14
Make a ten first: move 1 from the 5 over to the 9 to make 10 + 4, which equals 14. Making ten is a fast way to add larger sums.
6. 5 + 9 = 14
Flipping 9 + 5 gives 5 + 9, and the sum is still 14. Adding the same parts in any order never changes the whole.
7. 14 - 9 = 5
Think of 9 + ? = 14 and count up from 9: 10, 11, 12, 13, 14, which is 5 jumps. So 14 - 9 = 5.
8. 14 - 5 = 9
Subtract the 5 part from the whole 14, and the 9 part stays behind. Together, 5, 9, and 14 form a complete fact family.
9. 8 + 7 = 15
Use near-doubles: 7 + 7 is 14, so 8 + 7 must be one more, giving 15. This starts the 7, 8, 15 fact family.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
3 + 9
→ 12
7
15 - 8
→ 7
8
6 + 5
→ 11
11
17 - 9
→ 8
12
Solve each fact, then draw a line: 3 + 9 counts up to 12, 15 - 8 steps back to 7, 6 + 5 is one more than the double 5 + 5 to make 11, and 17 - 9 leaves 8. Each matching pair comes from its own fact family.