1.13 Rounding off the Digits
When rounding off numbers to a certain number of significant figures, do so to the nearest value. If the last digit is more than 5, the retained digit is increased by one, and if it is less than 5, it is retained as such.
Examples:
(i) Round off to 2 significant figures: 2.512 × 10³ m
Answer: 2.5 × 10³ m
(ii) Round off to 3 significant figures: 3.4567 × 10⁴ kg
Answer: 3.46 × 10⁴ kg