This study notes covers Worked Example: Significant Figures 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 4 of 6 in this topic. Use this study notes to connect the idea to the wider topic before moving on to questions and flashcards.
Worked Example: Significant Figures
Round 0.005372 to 2 significant figures
Step 1 Find first significant figure
Skip the zeros: 0.005372
5 is the 1st significant figure
Step 2 Identify 2nd s.f. and look at the next digit
0.005372 → 3 is 2nd s.f., look at 7
Step 3 Apply the rule
7 ≥ 5, so round UP: 3 becomes 4
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.