Percents — Drills
Percents has 6 drill skills. Each one generates fresh questions every time, with a hint and full worked steps, so you can keep practising a single skill until it settles.
What these drills cover
These questions use 2 ideas from the course. Follow any of them for a definition, where it is taught, and what it leads to.
- Percent — Parts per hundred. 37% = 37100 = 0.37.
- Percent increase — How much something grew, as a percentage of what it was.
Of
Unlimited questions of this kind are generated in the app. Two examples:
Problem 1
Find 35% of 240.
Worked answer
84
10% of 240 is 24
So 35% is 84
Problem 2
Find 60% of 160.
Worked answer
96
10% of 160 is 16
So 60% is 96
Converting units
Unlimited questions of this kind are generated in the app. Two examples:
Problem 1
Write 0.83 as a percent. Give just the number.
Worked answer
83
0.83 × 100 = 83
Problem 2
Write 13% as a decimal.
Worked answer
0.13
Move the point two places left: 0.13
Discount
Unlimited questions of this kind are generated in the app. Two examples:
Problem 1
A $100 item is reduced by 25%. Find the sale price.
Worked answer
75
100 × 0.75 = 75
Problem 2
A $80 item is reduced by 40%. Find the sale price.
Worked answer
48
80 × 0.6 = 48
Increase
Unlimited questions of this kind are generated in the app. Two examples:
Problem 1
A $100 price rises by 20%. Find the new price.
Worked answer
120
100 × 1.2 = 120
Problem 2
A $80 price rises by 25%. Find the new price.
Worked answer
100
80 × 1.25 = 100
Change
Unlimited questions of this kind are generated in the app. Two examples:
Problem 1
A price falls from $60 to $48. Find the percent decrease.
Worked answer
20
Change = 12
1260 = 0.2, so 20%
Problem 2
A price falls from $50 to $30. Find the percent decrease.
Worked answer
40
Change = 20
2050 = 0.4, so 40%
Working backwards
Unlimited questions of this kind are generated in the app. Two examples:
Problem 1
After 10% off, an item costs $90. What was the original price?
Worked answer
100
90 ÷ 0.9 = 100
Adding the percent back would give a different, wrong number
Problem 2
After 25% off, an item costs $60. What was the original price?
Worked answer
80
60 ÷ 0.75 = 80
Adding the percent back would give a different, wrong number