Study Guides

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 recognise when values have been rounded and state sensible suggestions of what the unrounded value could have been.

Key Notes

• When a number has been rounded you can make conjectures about what the unrounded number could have been.
• Rounding can be very useful in real life contexts particularly measure.
• When working in some real life contexts you are often working to a certain degree of accuracy.
• Numbers in different contexts will be rounded to a different degree of accuracy (e.g. distance when walking or flying).

Vocabulary To Learn

• Conjecture: A (mathematical) statement that is thought to be true but has not been proved yet.
• Degree of accuracy: A degree of accuracy shows how precise a number or measurement is. E.g. to the nearest cm, nearest 10, 1 d.p., etc.

Common Mistakes To Avoid

• The assumption that if a number ends in 2 zeros it must have been rounded to the nearest hundred.

3 Quick Questions (With Answers)

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
• Rounding to three decimal places Study Guide
• Truncating Study Guide
• Using inequality notation for errors in calculations Study Guide