Concept · 3 steps · NESA MA4-FRC-C-01

Rounding Decimals to a Given Accuracy

Measurements are almost never perfectly tidy, so we trim them to a sensible number of places. It sounds fiddly, but underneath it's one honest question: which round number are you nearest?

1Where it comes fromRounding is just "which marker on the number line are you closest to?" Drag and see. 2How to do itThe one rule: look at the next digit. 5 or more rounds up, less than 5 rounds down. 3Where it gets trickyWhen a 9 carries (9.96 → 10.0), why trailing zeros stay, and never double-round.

← This concept rests on

Place Value
Comparing Decimals

→ It unlocks

Significant Figures
Estimating Answers
Sensible Accuracy in Measurement