The Open University since 2006
Alternatively you can skip the navigation by pressing 'Enter'.
Thinking Allowed July 2016: Food bank Britain, Food poverty in EuropeMonday, 25th July 2016 00:15 - BBC Radio 4This episode looks at food poverty in Britain and Europe. Read more: Thinking Allowed July 2016: Food bank Britain, Food poverty in Europe
Full Steam Ahead: Episode oneAvailable until Monday, 22nd August 2016 17:30The first episode of Full Steam Ahead looks at the way Britain changed in the 19th century due to the railways Read more: Full Steam Ahead: Episode one
Thinking Allowed July 2016: Food bank Britain, Food poverty in EuropeAvailable for over a year
Exodus: Our Journey To Europe: EPISODE 3Available until Friday, 19th August 2016 01:15
Exodus: Our Journey To Europe: EPISODE 2Available until Friday, 19th August 2016 00:15
OpenLearn Live: 22nd July 2016A biochemist with a fearsome reputation; how drones are helping ferrets and keeping your workers... Read more: OpenLearn Live: 22nd July 2016
Full Steam AheadIt’s Full Steam Ahead for historians Ruth Goodman, Alex Langlands and Peter Ginn as they bring... Read more: Full Steam Ahead
Employment relations and employee engagementThis free course, Employment relations and employee engagement, looks at raising levels of... Try: Employment relations and employee engagement now
Introduction to cyber securityThis free course, Introduction to cyber security, will help you to understand online security and... Try: Introduction to cyber security now
Scientific calculators are a wonderful invention, but theyre only as good as the people who use them. If you often get an unexpected or ridiculous result when you press the enter button, this free course, Rounding and estimation, is for you. Learn how to do a calculation correctly and get the right answer every time.
After studying this course, you should be able to:
- round a given whole number to the nearest 10, 100, 1000 and so on
- round a decimal number to a given number of decimal places or significant figures
- use rounded numbers to find rough estimates for calculations
- use a calculator for decimal calculations involving +, −, × and ÷, giving the answer to a specified accuracy (e.g. decimal places or significant figures) and checking the answer by finding a rough estimate
- check the answers to calculations by ensuring that the correct calculation has been done, in the correct order.
- Current section: Introduction
- Learning outcomes
- 1 Rounding
- 1.1 Rounding in daily life
- 1.2 Rounding whole numbers
- 1.3 Rounding in general
- 1.4 Rounding decimals
- 1.5 Significant figures
- 1.6 Significant figures for numbers less than one
- 2 Estimation
- 3 Checking your answers
- 3.1 Have I done the right calculation?
- 3.2 Have I used the correct order for my calculation?
- 3.3 Have I given due consideration to units of measurement?
- 3.4 Did I make a rough estimate to act as a check?
- 3.5 Does the answer make sense in the real world?
- 3.6 Additional practice
- 4 OpenMark quiz
- Keep on learning
Study this free course
Enrol to access the full course, get recognition for the skills you learn, track your progress and on completion gain a statement of participation to demonstrate your learning to others. Make your learning visible!
Rounding and estimation
For many calculations you use a calculator. The main aim of this course is to help you to do this in a sensible and fruitful way. Using a calculation to solve a problem involves four main stages:
Stage 1: working out what calculation you want to do;
Stage 2: working out roughly what size of answer to expect from your calculation;
Stage 3: carrying out the calculation;
Stage 4: interpreting the answer – Does it agree with the rough estimate? Does it make sense in terms of the original problem?
This course focuses on Stages 2 and 4.
This OpenLearn course provides a sample of level 1 study in.
This free course includes adapted extracts from an Open University course which is no longer available to new students. If you found this interesting you could explore more free Mathematics Education courses or view the range of currently available OU Mathematics Education courses.
Copyright & revisions
Originally published: Friday, 10th June 2011
Last updated on: Wednesday, 23rd March 2016
- Creative-Commons: The Open University is proud to release this free course under a Creative Commons licence. However, any third-party materials featured within it are used with permission and are not ours to give away. These materials are not subject to the Creative Commons licence. See terms and conditions. Full details can be found in the Acknowledgements and our FAQs section.
- This site has Copy Reuse Tracking enabled - see our FAQs for more information.
If you enjoyed this, why not follow a feed to find out when we have new things like it? Choose an RSS feed from the list below. (Don't know what to do with RSS feeds?)
Remember, you can also make your own, personal feed by combining tags from around OpenLearn.
All our alternative formats are free for you to download, for more information about the different formats we offer please see our FAQs. The most frequently used are Word (for accessibility), PDF (for print) and ePub and Kindle to download to eReaders*.
- Word (1.4 MB)
- PDF (2.6 MB)
- ePub 3.0 (1.1 MB)
- ePub 2.0 (1.1 MB)
- Kindle (745 KB)
- RSS (349 KB)
- HTML (1.1 MB)
- SCORM (1.1 MB)
- OUXML Package (31 KB)
- OUXML File (136 KB)
- IMS Common cartridge
*Please note you will need an ePub and Mobi reader for these formats.