Relate Multiplication and Division
You can use fact families to find unknown factors.
EXAMPLE
Write the fact family for each array or set of numbers.
3 × 7 = 21 7 × 3 = 21
21 ÷ 3 = 7 21 ÷ 7 = 3
Let's Practice Together
1. Write the fact family that describes the array below.
2. Write the fact family that describes the array below.
Your Turn
3. Write a fact family that uses the numbers below.
3, 7, 21
4. Write a fact family that uses the numbers below.
3, 5, 15
5. Write a fact family that uses the numbers below.
4, 8, 32
6. Complete the fact family.
6 x 3 = ? ? 3 = 6
3 x ? = 18 18 ? = 3
7. Complete the fact family.
7 x 2 = ? ? 2 = 7
2 x ? = 14 14 ? = 2
8. Complete the fact family.
6 x 4 = ? ? 6 = 4
4 x ? = 24 24 ? = 6
Check for Understanding
1. There are 5 rows and 7 chairs in each row. What fact family can you write with this information?
Answers
1.
8 x 2 = 16
2 x 8 = 16
16 ÷ 8 = 2
16 ÷ 2 = 8
2.
9 x 4 = 36
4 x 9 = 36
36 ÷ 9 = 4
36 ÷ 4 = 9
3.
3 x 7 = 21
7 x 3 = 21
21 ÷ 7 = 3
21 ÷ 3 = 7
4.
3 x 5 = 15
5 x 3 = 15
15 ÷ 3 = 5
15 ÷ 5 = 3
5.
4 x 8 = 32
8 x 4 = 32
32 ÷ 8 = 4
32 ÷ 4 = 8
6.
6 x 3 = 18
3 x 6 = 18
18 ÷ 3 = 6
18 ÷ 6 = 3
7.
7 x 2 = 14
2 x 7 = 14
14 ÷ 2 = 7
14 ÷ 7 = 2
8.
6 x 4 = 24
4 x 6 = 24
24 ÷ 6 = 4
24 ÷ 4 = 6
Check for Understanding
1.
5 x 7 = 35
7 x 5 = 35
35 ÷ 7 = 5
35 ÷ 5 = 7