1

90 students in a school have visited at least two other provinces.

If this represents 24% of the students

in the school, how many students are in the school?

Choice A

2

Possible Strategies – Estimation 24 % ≈ 25 % or ¼

90 90 90 90

Whole school

Which is approximately 360.

Hence the whole school is < 360? > 360?

3

Diagram24% 90 students

96 % 360 students

4% 15 students

100% 375 students

4×24 4×90

24/6 90/6

9090

9090

15

4

Diagram• 24% = 24/100 = 6/25 (1 colour group)• 4 colour groups fit in a 5×5 square• Each colour group represents 90 students • Coloured squares: 4×90 = 360 students• 1 square is not coloured• Each square is 1/6 of 90 = 15 students

So, total is 360 (coloured) + 15 (not coloured) = 375 students

5

Number Line

24 % 24 % 24 % 24 % 4 %

90 90 90 90 15

96 %

360

375

6

Friendly Numbers

• 24% = 90 students • 12% = 45 students• 4% = 15 students• 100% = 375 students

÷2

÷3

×25

7

Double Number Line

4%

15 90

24% 100%

375

÷6

÷6

×25

×25

Ratio Tables

90

24 %

÷ 2

÷ 2

÷ 3

÷ 3

× 25

× 25

45

12% 100%

375

4%

15

9

Elastic Meter Manipulative100

24

x 90

=

Elastic Metre