Bounds
- Find half of the rounding unit.
- Subtract for lower bound.
- Add for upper bound.
Answer: 8.0 to nearest tenth has bounds 7.95 and 8.05
🔢 Number
Bounds
Learn bounds with a GCSE-style explanation, help guide, worked example, practice question and flashcards.
Global XP
Level 10 / 100 XP
1. Explanation
Key idea
- Bounds is part of advanced topics and appears often in KS3–GCSE maths.
- Bounds show the interval of possible exact values after rounding.
- Use the worked model, help guide, interactive question and flashcards to practise bounds until the steps feel automatic.
Real-life examples
- Shopping, sport, travel, science, design and everyday decisions all use this skill.
2. Visual
Bounds 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 Bounds
- Learn the rule: Bounds show the interval of possible exact values after rounding.
- Worked model: Find half of the rounding unit. Subtract for lower bound. Add for upper bound.
- 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
A length is 12 cm to the nearest cm. What is the lower bound?
6. Flashcards
Master quick recall
Flip each card, then choose whether you know it or need more practice.
0 mastered
FrontRule for Bounds
BackBounds show the interval of possible exact values after rounding.
FrontExample answer: A length is 12 cm to the nearest cm. What is the lower bound?
BackValues from 11.5 cm up to 12.5 cm round to 12 cm, so the lower bound is 11.5 cm.
FrontCommon check for Bounds
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.