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NumberIntroduction

Why Round Numbers?

Part of Rounding & Estimation — GCSE Mathematics

This introduction covers Why Round Numbers? 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 1 of 5 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 1 of 5

Practice

13 questions

Recall

6 flashcards

Why Round Numbers?

Your calculator says π = 3.141592653589793... but you can't write that in every answer! Rounding gives us sensible, usable numbers. Whether it's 2 decimal places for money or 3 significant figures for science, rounding is essential.
Rounding rules - decimal places, significant figures, the 5-or-more rule

Keep building this topic

Read this section alongside the surrounding pages in Rounding & Estimation. That gives you the full topic sequence instead of a single isolated revision point.

The Key RuleTypes of RoundingWorked Example: Significant Figures

Practice Questions for Rounding & Estimation

Round 4.673 to 1 decimal place.

  • A. 4.6
  • B. 4.7
  • C. 4.67
  • D. 5.0
1 markfoundation

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.

2 marksstandard

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

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The Key Rule