Cogito
Grade 3 Math · Chapter 1 · Lesson 5
Multiplication and Division Fact Families
Four facts from one array.
10 problems · about 12 minutes · 3.OA.A.4, 3.OA.B.6
What this lesson teaches
The child writes the four related multiplication and division equations for a given array.
- Three numbers make four facts.
- Two multiplications and two divisions.
- Learning one hands you the other three.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
2 problemsReview — Division as an Unknown Factor: 45 ÷ 5 = ?
Answer 9
Why 9 × 5 = 45.
Review — Division as Sharing: 24 ÷ 4 = ?
Answer 6
Why 24 ÷ 4 = 6.
Warm Up
Straightforward practice. Get the method working first.
4 problemsYou know 6 × 4 = 24. What is 24 ÷ 6?
Answer 4
Why 24 ÷ 6 = 4.
How many facts come from the numbers 3, 5 and 15?
Answer 4
Why 3 × 5, 5 × 3, 15 ÷ 3, and 15 ÷ 5.
You know 5 × 8 = 40. What is 40 ÷ 8?
Answer 5
Why The other factor.
You know 9 × 2 = 18. What is 18 ÷ 9?
Answer 2
Why The other factor.
Build It Up
The same ideas with more to keep track of.
2 problemsHow many facts come from one array?
Answer 4
Why Two multiplying, two dividing.
4 and 7 make 28. What is 28 ÷ 4?
Answer 7
Why The other factor.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
2 problemsUsing the Family: You know 7 × 3 = 21. What is 21 ÷ 7?
Answer 3
Why 21 ÷ 7 = 3, straight from the family.
The Other Way: You know 6 × 5 = 30. What is 30 ÷ 5?
Answer 6
Why 30 ÷ 5 = 6.