What you’ll learn
Choose appropriate level of precision.
Key idea
Calculator digits do not create measurement precision; follow the explicitly stated approximate reporting rule.
Arithmetic precision does not establish exact physical measurement; retain units and the stated approximate reporting resolution.
Worked example
Classify examples and non-examples for the concept 'Choose appropriate level of precision'.
Square side 2.6 m measured to nearest tenth meter; report approximate area to nearest tenth square meter. Classify whether this claim is justified: physical area is exactly 6.760000 m².
- Recorded side 2.6 m squared gives arithmetic result 6.76 m², but the side was measured only to a tenth of a meter.
- Under the stated nearest-tenth area reporting rule, report about 6.8 m². Recorded whole-minute times [26, 30, 31] have mean 29, reported about 29 minutes under the nearest-minute policy.
Answer: No — limited measurement resolution requires an approximate report under the stated policy.
Quick Check
Classify examples and non-examples for the concept 'Choose appropriate level of precision'.
Square side 1.2 m measured to nearest tenth meter; report approximate area to nearest tenth square meter. Classify whether this claim is justified: physical area is exactly 1.440000 m².