- WRONG: Counting leading zeros as significant (0.005 has 1 s.f., not 3)
- WRONG: Forgetting trailing zeros matter in s.f. (3.50 has 3 s.f., not 2)
- RIGHT: For estimation, round to 1 s.f. to make calculation easy
This exam tips covers Common Mistakes within Rounding & Estimation for GCSE Mathematics. Revise Rounding & Estimation in Number for GCSE Mathematics with 13 exam-style questions and 6 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 5 of 6 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Practice questions for Rounding & Estimation
Round 4.673 to 1 decimal place.
A student says '3.50 and 3.5 are exactly the same number so they have the same number of significant figures.' Explain why the student is wrong.
Quick recall flashcards
Estimation
Round each number to 1 s.f., then calculate
Rounding Rule
Look at the next digit: 0-4 round down, 5-9 round up