Grade 5 · Math · Unit 3 of 13
Mental Math Tricks
Facts to 81 and clever shortcuts
What your child practises
Recalling multiplication and division facts to 9 × 9, and mental strategies such as adding zeros, halving and doubling, and breaking a number into friendly parts.
New Brunswick Curriculum skill descriptor: Number: Operations · mental math strategies for multiplication and division facts
Sample questions
A taste of this unit. In the app, questions change every time and get easier or harder to match your child.
Question 1
36 × 5 is the same as half of 36 × ?
- 10
- 5
- 20
10
Hint: 5 is half of 10, so 36 × 5 is half of 36 × 10.
Question 2
8 × 9 = ?
- 81
- 72
- 64
72
Hint: 8 × 10 = 80, then take away 8.
Question 3
6 × 40 = ?
- 24
- 2 400
- 240
240
Hint: Do 6 × 4 = 24, then add one zero.
Question 4
12 × 5 = ?
- 60
- 50
- 72
60
Hint: Half of 12 × 10 = 120 is 60.
Question 5
7 × 200 = ?
- 1 400
- 14 000
- 140
1 400
Hint: 7 × 2 = 14, then add two zeros.
Question 6
480 ÷ 6 = ?
- 800
- 8
- 80
80
Hint: 48 ÷ 6 = 8, then add one zero.