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Percent Drill asks the question that comes up most often away from a desk: what is 15% of 60? Percentages are the arithmetic of tips, discounts, interest and statistics, and almost all of them collapse to a couple of easy steps once you stop reaching for a calculator. Sixty seconds, one percentage at a time, with the working shown whenever you miss one.
Choose easy percentages, awkward ones or reverse questions, then press Start.
Each question asks for a percentage of a number.
Type the answer; a correct one moves straight to the next question.
A miss shows the route — usually via 10% or 1%.
Your score is percentages answered correctly in the minute.
Proportional reasoning done in steps rather than in one leap. Working out 35% by taking 10% three times and adding half of one of them is the habit that makes percentages quick, and it is what this drill builds.
Find 10% first — move the decimal point one place left. Everything else is built from that.
1% is 10% of 10%, which gives you the awkward figures: 17% is 10% + 5% + 2%.
Percentages commute: 8% of 50 is the same as 50% of 8, which is 4. Flipping the question often makes it trivial.
For a discount, work out what you pay rather than what you save — 30% off is 70% of the price, which is one step instead of two.
Start from 10%, which is the number with the decimal point moved one place left, then build up. 30% is three lots of 10%; 5% is half of 10%; 1% is a tenth of 10%.
If 20 is 25% of a number, multiply by 4 to get 80. In general, divide by the percentage and multiply by 100.
Because x% of y and y% of x are the same multiplication written in a different order. 8% of 50 and 50% of 8 both come to 4.
In the easy and awkward levels, yes. The reverse level can produce answers with one decimal place, and the drill accepts a decimal point in your answer.