Worksheets · Geometry

Greatest possible error worksheet

A measurement is only as exact as the unit it was taken to. Measured to the nearest centimeter, a length written as 12 cm could really be anything from 11.5 to 12.5 cm, so the greatest possible error is half of that unit. The percent error compares that error with the measurement itself.

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Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep

Sigma Prep · sigmaprep.io/worksheets

Name

Greatest Possible Error

Date Period

Answer each question about the measurement.

  1. A length is measured as 2.1 m, to the nearest tenth of a meter. Find the greatest possible error, in meters.
  2. A length is measured as 39.3 m, to the nearest tenth of a meter. Find the percent error, to the nearest tenth of a percent.
  3. A length is measured as 270 ft, to the nearest 10 feet. What are the least and greatest lengths it could really be?
  4. A length is measured as 29.4 m, to the nearest tenth of a meter. Find the greatest possible error, in meters.
  5. A length is measured as 39.9 cm, to the nearest tenth of a centimeter. Find the percent error, to the nearest tenth of a percent.
  6. A length is measured as 20.6 cm, to the nearest tenth of a centimeter. What are the least and greatest lengths it could really be?
  7. A length is measured as 26 cm, to the nearest centimeter. Find the greatest possible error, in centimeters.
  8. A length is measured as 11 in, to the nearest inch. Find the percent error, to the nearest tenth of a percent.
  9. A length is measured as 4.5 cm, to the nearest tenth of a centimeter. What are the least and greatest lengths it could really be?
  10. A length is measured as 31.2 cm, to the nearest tenth of a centimeter. Find the greatest possible error, in centimeters.
  11. A length is measured as 14 in, to the nearest inch. Find the percent error, to the nearest tenth of a percent.
  12. A length is measured as 27 cm, to the nearest centimeter. What are the least and greatest lengths it could really be?
  13. A length is measured as 32.4 m, to the nearest tenth of a meter. Find the greatest possible error, in meters.
  14. A length is measured as 22.8 m, to the nearest tenth of a meter. Find the percent error, to the nearest tenth of a percent.
  15. A length is measured as 0.93 m, to the nearest hundredth of a meter. What are the least and greatest lengths it could really be?
  16. A length is measured as 1.93 m, to the nearest hundredth of a meter. Find the greatest possible error, in meters.
  17. A length is measured as 3.98 m, to the nearest hundredth of a meter. Find the percent error, to the nearest tenth of a percent.
  18. A length is measured as 46 in, to the nearest inch. What are the least and greatest lengths it could really be?
  19. A length is measured as 21 cm, to the nearest centimeter. Find the greatest possible error, in centimeters.
  20. A length is measured as 11.4 cm, to the nearest tenth of a centimeter. Find the percent error, to the nearest tenth of a percent.

Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep

Sigma Prep · sigmaprep.io/worksheets

Name

Greatest Possible ErrorAnswer keyVersion 1

Date Period

Answer each question about the measurement.

  1. A length is measured as 2.1 m, to the nearest tenth of a meter. Find the greatest possible error, in meters.0.05
  2. A length is measured as 39.3 m, to the nearest tenth of a meter. Find the percent error, to the nearest tenth of a percent.0.1
  3. A length is measured as 270 ft, to the nearest 10 feet. What are the least and greatest lengths it could really be?265 ft to 275 ft
  4. A length is measured as 29.4 m, to the nearest tenth of a meter. Find the greatest possible error, in meters.0.05
  5. A length is measured as 39.9 cm, to the nearest tenth of a centimeter. Find the percent error, to the nearest tenth of a percent.0.1
  6. A length is measured as 20.6 cm, to the nearest tenth of a centimeter. What are the least and greatest lengths it could really be?20.55 cm to 20.65 cm
  7. A length is measured as 26 cm, to the nearest centimeter. Find the greatest possible error, in centimeters.0.5
  8. A length is measured as 11 in, to the nearest inch. Find the percent error, to the nearest tenth of a percent.4.5
  9. A length is measured as 4.5 cm, to the nearest tenth of a centimeter. What are the least and greatest lengths it could really be?4.45 cm to 4.55 cm
  10. A length is measured as 31.2 cm, to the nearest tenth of a centimeter. Find the greatest possible error, in centimeters.0.05
  11. A length is measured as 14 in, to the nearest inch. Find the percent error, to the nearest tenth of a percent.3.6
  12. A length is measured as 27 cm, to the nearest centimeter. What are the least and greatest lengths it could really be?26.5 cm to 27.5 cm
  13. A length is measured as 32.4 m, to the nearest tenth of a meter. Find the greatest possible error, in meters.0.05
  14. A length is measured as 22.8 m, to the nearest tenth of a meter. Find the percent error, to the nearest tenth of a percent.0.2
  15. A length is measured as 0.93 m, to the nearest hundredth of a meter. What are the least and greatest lengths it could really be?0.925 m to 0.935 m
  16. A length is measured as 1.93 m, to the nearest hundredth of a meter. Find the greatest possible error, in meters.0.005
  17. A length is measured as 3.98 m, to the nearest hundredth of a meter. Find the percent error, to the nearest tenth of a percent.0.1
  18. A length is measured as 46 in, to the nearest inch. What are the least and greatest lengths it could really be?45.5 in to 46.5 in
  19. A length is measured as 21 cm, to the nearest centimeter. Find the greatest possible error, in centimeters.0.5
  20. A length is measured as 11.4 cm, to the nearest tenth of a centimeter. Find the percent error, to the nearest tenth of a percent.0.4

Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep

How to do these

A length is measured as 4.5 m, to the nearest tenth of a meter. Find the greatest possible error and the percent error.

  1. Half of a tenth is 0.05, so the greatest possible error is 0.05 m.
  2. Percent error: 0.05 divided by 4.5, times 100, is about 1.1%.

The answer is 0.05 m, about 1.1%.

Where students go wrong

Using the whole unit instead of half of it. A length measured to the nearest inch is off by at most half an inch either way, not a full inch.

Also called greatest possible error, percent error, precision of a measurement, measurement error or tolerance.

What you can put on this worksheet

Greatest possible error
A length is measured as 35 in, to the nearest inch. Find the greatest possible error, in inches. → 0.5
Percent error from the precision
A length is measured as 35 in, to the nearest inch. Find the percent error, to the nearest tenth of a percent. → 1.4
The least and greatest the length could be
A length is measured as 35 in, to the nearest inch. What are the least and greatest lengths it could really be? → 34.5 in to 35.5 in

Questions about these worksheets

Yes. Every greatest possible error sheet is free to print and free to download as a PDF. There is no account to make, no email to hand over and no limit on how many you take.

Yes. The answer key prints on a second page, and you can choose whether it shows each question beside its answer or just the answers in a list.

Yes. Print straight from the page, or download the PDF and print that. The sheet is laid out for paper rather than squeezed off a screen, so there is room to work under each question, and the answer key comes out on its own page.

Geometry is usually taken around 9th or 10th grade, though schools vary and plenty of students meet it earlier or later. Pick the difficulty rather than the grade: the easy level suits a first lesson on it, the hard level suits review before a test.

Yes, as many as you like. The questions are built fresh each time rather than picked from a fixed set of files, so pressing Generate gives a new sheet. That is what you want for a second class, a retake, or two students sitting next to each other.

That is the closest comparison, and Kuta Software is good software. It is also paid software you install on a computer. These worksheets run in a browser tab for free, with no account and nothing to install. Like Kuta, the greatest possible error questions are generated when you ask for them rather than pulled from a fixed set of files, so two classes never get the same sheet, and the answer key comes with it.

Yes. There are three levels, and you can tick more than one for a sheet that mixes them, in which case the questions come out easiest first. The harder levels are not just larger numbers: they ask for something the easy ones do not.

You pick from 3: greatest possible error, percent error from the precision and the least and greatest the length could be. Tick as many as you want and set how many of each, or let it spread them evenly.

Using the whole unit instead of half of it. A length measured to the nearest inch is off by at most half an inch either way, not a full inch.