Estimate an answer
- Round numbers to friendly values.
- Calculate mentally.
- Use it to judge the exact answer.
Answer: 198 ÷ 4 ≈ 200 ÷ 4 = 50
🔢 Number
Estimation
Learn estimation with a GCSE-style explanation, help guide, worked example, practice question and flashcards.
Global XP
Level 10 / 100 XP
1. Explanation
Key idea
- Estimation is part of number and appears often in KS3–GCSE maths.
- Estimation gives a sensible approximate answer.
- Use the worked model, help guide, interactive question and flashcards to practise estimation until the steps feel automatic.
Real-life examples
- Shopping, sport, travel, science, design and everyday decisions all use this skill.
2. Visual
Estimation learning map
Understand the key idea → follow the help guide → practise a question → check your method → build speed with flashcards.
3. Help guide
How to tackle Estimation
- Learn the rule: Estimation gives a sensible approximate answer.
- Worked model: Round numbers to friendly values. Calculate mentally. Use it to judge the exact answer.
- Try the interactive question without looking at the answer first.
- Use the flashcards to test the rule, the method and a common check.
4. Worked examples
Step-by-step working
5. Interactive questions
Try it yourself
Estimate 49 × 21.
6. Flashcards
Master quick recall
Flip each card, then choose whether you know it or need more practice.
0 mastered
FrontRule for Estimation
BackEstimation gives a sensible approximate answer.
FrontExample answer: Estimate 49 × 21.
Back49 ≈ 50 and 21 ≈ 20, so 49 × 21 ≈ 50 × 20 = 1000.
FrontCommon check for Estimation
BackCheck units/notation, compare with an estimate, and make sure the answer matches the question.
7. Finish
Complete this topic
When you have read the examples, tried the question and reviewed flashcards, claim your topic completion XP.