Percent error says how far a measurement missed by, as a share of the true value. These free printable worksheets give the actual and measured amounts and ask for that percent — every answer a whole number.
The reliable mistake is dividing by the wrong number, so the two are always named. The gap between measured and actual is divided by the ACTUAL value — the true one — not by the measurement that missed. A child who divides by the measured value gets a close-but-wrong answer every time, which is exactly why the sheet labels which is which on every question.
Why this sheet works
Two steps, in order. First the size of the gap, with the sign thrown away, because a reading three below the true value is as wrong as one three above — |measured − actual|. Then that gap as a percent of the actual value. Written out, the second step is a percent-of-a-number in reverse, which is the skill the sheet leans on.
How this one works
One question from this sheet, worked through a step at a time.
The true value is 420, but it was measured as 441.
441 − 420=21
21÷420× 100 =5%
Percent error starts from the gap between the two readings — the bigger take away the smaller: 441 − 420 = 21.
Now write that gap as a percent of the ACTUAL value — the true one, not the measured one: 21 ÷ 420 × 100 = 5%.
1The true value is 420, but it was measured as 441.What is the percent error?
2The true value is 75, but it was measured as 78.What is the percent error?
3The true value is 90, but it was measured as 72.What is the percent error?
4The true value is 400, but it was measured as 432.What is the percent error?
5The true value is 500, but it was measured as 480.What is the percent error?
Percent word problems · Percent errorAnswer key
1. The true value is 420, but it was measured as 441. What is the percent error? → 5%2. The true value is 75, but it was measured as 78. What is the percent error? → 4%3. The true value is 90, but it was measured as 72. What is the percent error? → 20%4. The true value is 400, but it was measured as 432. What is the percent error? → 8%5. The true value is 500, but it was measured as 480. What is the percent error? → 4%
