Cogito
Grade 3 Math · Chapter 1 · Lesson 7
Dividing by 2, 5, and 10
The same three tables, read backwards.
10 problems · about 12 minutes · 3.OA.C.7, 3.OA.B.6
What this lesson teaches
The child divides by 2, 5, and 10 by recalling the matching multiplication fact.
- Dividing by 2 is halving.
- Dividing by 10 asks how many tens.
- Every division is answered by a fact you already know.
Warm-Up Review
From earlier lessons. Loosen up before the new work.
2 problemsReview — Multiplying by 2, 5, and 10: 7 × 5 = ?
Answer 35
Why 7 × 5 = 35.
Review — Multiplication and Division Fact Families: You know 6 × 4 = 24. What is 24 ÷ 6?
Answer 4
Why 24 ÷ 6 = 4.
Warm Up
Straightforward practice. Get the method working first.
4 problems40 ÷ 5 = ?
Answer 8
Why 8 × 5 = 40.
What is dividing by 2 the same as?
Answer Halving.
Why Splitting into two equal shares is halving.
14 ÷ 2 = ?
Answer 7
Why Half of 14.
30 ÷ 5 = ?
Answer 6
Why What times 5 makes 30?
Build It Up
The same ideas with more to keep track of.
2 problems80 ÷ 10 = ?
Answer 8
Why How many tens in 80?
50 ÷ 5 = ?
Answer 10
Why Ten fives.
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
2 problemsFair Shares: 16 apples are shared equally between 2 people. How many each?
Answer 8 apples
Why 16 ÷ 2 = 8.
Coins Again: Leo has 45 pence, all in 5p coins. How many coins?
Answer 9 coins
Why 45 ÷ 5 = 9 coins.