Year 8 - Maths
Rounding to three decimal places
Estimation and rounding
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
This unit helps pupils understand rounding to different decimal places, and significant figures. Pupils will also learn how to truncate numbers and understand the contexts in which these skills are useful. The unit ends will an exploration of rounding and inequality errors.
Lesson Summary
You will learn to round numbers to three decimal places.
Key Notes
- Numbers with any number of decimal places can be represented on a number line.
- Rounding is useful to estimate numbers to a degree of accuracy.
- Numbers can be rounded to 3 decimal places.
- Knowing a number has been rounded means you can give examples of what the unrounded number might have been.
Vocabulary To Learn
- Round: To change a number into another number that is approximately the same value but is easier to work with. E.g. round 561 to the nearest 10 is 560.
Common Mistakes To Avoid
- Errors when a zero is required when rounding. E.g 5.99 rounds to 6 to 1 d.p.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Numbers with any number of decimal places can be represented on a number line. Rounding is useful to estimate numbers to a degree of accuracy.
2. Use this key word in a maths sentence and explain it clearly. 'Round'
To change a number into another number that is approximately the same value but is easier to work with. E.g. round 561 to the nearest 10 is 560. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Errors when a zero is required when rounding. E.g 5.99 rounds to 6 to 1 d.p. Correction: Embedding that 6 and 6.0 may be written like that to convey the accuracy they've been rounded to. To show that 5.99 has been rounded to 1 d.p. we write it as 6.0 not 6.
More Lessons In This Unit
- Checking by estimating Study Guide
- Checking understanding of rounding Study Guide
- Degrees of accuracy Study Guide
- Estimating numerical calculations Study Guide
- Inequality notation to express error Study Guide
- Overestimating vs underestimating Study Guide
- Problem solving with estimation and rounding Study Guide
- Rounding decimals to significant figures Study Guide
- Rounding errors Study Guide
- Rounding integers to one significant figure Study Guide
- Rounding integers to significant figures Study Guide
- Rounding to any number of decimal places Study Guide
- Securing understanding of rounding Study Guide
- Truncating Study Guide
- Using inequality notation for errors in calculations Study Guide
Browse all guides in the Year 8 Maths guide library.