Grade 7 · Math · Unit 11 of 20
Data & Percentages
Percents, circle graphs and outliers
What your child practises
Using percents to compare groups, turning circle-graph angles into percents, and seeing how adding or removing a value changes the mean and median.
Ontario Curriculum expectation: D1.1, D1.2, D1.5, D1.6 · percentages in data, circle graph angles, the effect of adding or removing data, and misleading graphs
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
In a survey of 250 students, 100 walk to school. What percent walk?
answer box%
Show answer
40 %
Hint: Write 100/250 as a fraction out of 100.
Question 2
A sector of a circle graph is 180°. What percent of the graph is that?
answer box%
Show answer
50 %
Hint: A whole circle is 360°. Divide the angle by 360.
Question 3
A circle graph's sectors add up to 120%. What is wrong?
- Circle graphs must have 12 sectors.
- The parts of a whole must add to 100%.
- Nothing is wrong.
Show answer
The parts of a whole must add to 100%.
Hint: Ask what was left out and how the scale was set.
Question 4
The data 3, 5, 10, 11 has a mean of 7.25. A new value of 30 is added. What happens to the mean?
- It goes down
- It stays the same
- It goes up
Show answer
It goes up
Hint: Compare the new value with the old mean. A value above the mean pulls it up. A value below pulls it down.
Question 5
The data 12, 6, 5, 28, 24 has a median of 12. After the least value (5) is removed, what is the new median?
answer box
Show answer
18
Hint: Put the remaining four numbers in order. With two middle numbers, find the number halfway between them.
Question 6
In a survey of 400 students, 60 walk to school. What percent walk?
answer box%
Show answer
15 %
Hint: Write 60/400 as a fraction out of 100.