MathIQO — Adaptive math practice for Ontario kids

MathIQO worksheet

Solve problems involving percentages, rates, and proportions · Grade 9 · B3.5

Name: ______________________

Date: ______________________

1
What is 40% of 80?
Warm-up
Answer:
2
What is 15% of 140?
Warm-up
Answer:
3
What is 5% of 160?
Warm-up
Answer:
4
6 notebooks cost $48. At the same rate, how much do 9 notebooks cost?
On level
Answer:
5
6 notebooks cost $30. At the same rate, how much do 2 notebooks cost?
On level
Answer:
6
6 notebooks cost $18. At the same rate, how much do 8 notebooks cost?
On level
Answer:
7
A jacket costs $180. Its price rises by 40%. What is the new price?
Challenge
Answer:
8
A jacket costs $100. Its price rises by 60%. What is the new price?
Challenge
Answer:
9
A jacket costs $180. Its price rises by 50%. What is the new price?
Challenge
Answer:

✅ Done? See how you did — check in at mathiqo.com/check-in

Worksheet code: eyJzIjoibnVtYmVyLXBlcmNlbnQtcHJvcG9ydGlvbiIsImQiOls1NDg4MjEzMDAsMTE4NjkyNjA5MiwxMjQ5Mjc0MjYsNjgyNjQzNjY2LDkyMDk1ODAwMSwxMjEyMTM3OTAwLDE2NzUxNjkzMzcsMTI3NTYwMjgwLDEyMzkxNzA5MDZdLCJ2IjoxfQ.23fd242f0a6d

A quick 5-question check-in grades itself instantly and shows what to practise next.

Answer key · Solve problems involving percentages, rates, and proportions

1.
32 — 40% of 80 = 40/100 × 80 = 32.
2.
21 — 15% of 140 = 15/100 × 140 = 21.
3.
8 — 5% of 160 = 5/100 × 160 = 8.
4.
72 — Each notebook costs $48 ÷ 6 = $8, so 9 cost 9 × $8 = $72.
5.
10 — Each notebook costs $30 ÷ 6 = $5, so 2 cost 2 × $5 = $10.
6.
24 — Each notebook costs $18 ÷ 6 = $3, so 8 cost 8 × $3 = $24.
7.
252 — The increase is 40% of $180 = $72, so the new price is $180 + $72 = $252.
8.
160 — The increase is 60% of $100 = $60, so the new price is $100 + $60 = $160.
9.
270 — The increase is 50% of $180 = $90, so the new price is $180 + $90 = $270.