1. Choice A
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?
<10 min.>
After 5 min. ask for volunteers to share their solutions on Doc. Camera if available. If not, then on chart paper.
This problem is intended to be a mathematically useful problem, but also to begin the discussion of anticipating student difficulties and, as a result, considering a parallel more appropriate task for some students.
The problem will be revisited to create a parallel task after discussion around potential student difficulties has happened.

2. Possible strategies- Estimation
24 % ≈ 25 % or ¼ 90
Whole school
Which is approximately 360.
Ask which it is < or >. Good reasoning question.
Since 24% is 90. The total is slightly more than 4 times 90, hence > 360.
Hence the whole school is < 360? > 360?

3. Diagram 90 90 24% 90 students 96 % 360 students 4% 15 students
4x24
4x90
24/6
90/6 15 90 90

4. Diagram 24% = 24/100 = 6/25 (1 colour group)
4 colour groups fit in a 5x5 square
each colour group represents 90 students
coloured sq’s: 4x90 = 360 students
but 1 square is uncloured
each square is 1/6 of 90 = 15 students
So, total is 360(coloured) + 15(uncloured)
= 375 students
Alternate presentation

5. Number Line
375
360 90 90 90 90 15
24 %
24 %
24 %
24 %
4 %
96 %

6. Friendly Numbers 24% = 90 students 12% = 45 students 4% = 15 students÷2 ÷3
X 25
Students may choose to work down and then up using friendly numbers.

7. Double Number Line x25 ÷6 4% 15 90 24% 375 100%
A similar representation is to use a ‘double number line’.

8. Ratio Tables
÷ 2
÷ 3
x 25 90
24 % 45
12% 4% 15
100%
375
A similar strategy can be arranged in a ratio table. Sample given in proportional package in appendices.
This graphic organizer is used to create equivalent ratios. Entries in a column are multiplied or divided by the same amount.

9. Elastic Meter Manipulative
100 24 x 90 =
Manipulative
The elastic meter is another organizer for students to use.
Students may find it useful when determining where to put the numbers in a ratio and then solve using a variety of strategies. Cross-multiply being one of then.
The Elastic Meter video (GAINS website- manipulatives) shows how this strategy can be used. Show video if possible.
Elastic Meter