CCSS.Math.Content.HSN-Q.A.3
The Standard
Choose a level of accuracy appropriate to limitations on measurement when reporting quantities.
Common Core State Standards for Mathematics · Quantities
Teacher's field guide
What This Standard Means
What Students Need to Do
- Students judge how precisely a quantity can be reported from the measuring tool and the situation. They round measured or calculated values without claiming unsupported accuracy.
What Mastery Looks Like
- Students report measurements and calculated results with precision supported by the measuring tool. They can explain why a rounded value is more defensible than a calculator display with many digits.
Common Misconceptions
- Students often copy every digit from a calculator, even when the measurements do not support that precision. They may think extra decimal places always make an answer more accurate. Some round measurements too early and distort the final result.
How to Assess It
- Exit ticket: A thermometer marked in 1°C intervals reads halfway between 21°C and 22°C. Ask students to report the temperature and explain their chosen precision.
Lesson moves
Ways to Teach It
Set up stations with rulers, scales, and measuring cups, then have students measure objects and justify every reported digit.
Ask students to compare 8.3472 meters and 8.3 meters for a tape measurement, then write which report is more defensible and why.
Give pairs cards showing instruments, measurements, and reported values, then award points for correctly matching each value to its instrument.
Use room dimensions measured to the nearest tenth of a meter, then have students calculate and appropriately report the flooring area.
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Printable HSN-Q.A.3 Worksheet
A ready-to-print activity worksheet aligned to CCSS.Math.Content.HSN-Q.A.3, with an answer key for the teacher on its own page. No account needed.
PDF, US Letter, prints cleanly in black and white.
Download the worksheetLearning progression
Where This Standard Sits
Before This Standard
If students are struggling here, check these first.
- CCSS.Math.Content.HSN-Q.A.1
Interpreting units and display scales supports judging measurement precision and how many digits a reported quantity should reasonably include.
- CCSS.Math.Content.HSN-Q.A.2
Students must identify the relevant quantities and units before deciding how precisely those measured quantities should be reported.
- CCSS.Math.Content.8.EE.A.4
Scientific notation and unit choice can support reporting measured quantities, but accuracy decisions mainly require understanding measurement limits and rounding.
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