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# Numbers, units and arithmetic

Do fractions and decimals make you apprehensive about maths? Do you lack confidence in...

Do fractions and decimals make you apprehensive about maths? Do you lack confidence in dealing with numbers? If so, then this unit is for you. The unit will explain the basics of working with positive and negative numbers and how to multiply and divide with fractions and decimals.

By the end of this unit you should be able to:

- write whole numbers and decimals in place-value columns and compare their sizes;
- multiply and divide whole numbers and decimals by 10, 100, 1000 and so on;
- indicate given fractions on a diagram and find equivalent fractions for a given fraction;
- mark numbers on a number line;
- choose appropriate units for a given purpose;
- convert between different metric units and different time units;
- perform, without a calculator, calculations involving: brackets, addition, subtraction, multiplication and division of whole numbers, decimals, simple fractions and negative numbers;
- describe in words the arithmetic processes that you use.

- Duration 5 hours
- Updated Thursday 17th October 2013
- Introductory level
- Posted under Mathematics Education

## Contents

- Current section: Introduction
- Learning outcomes
- 1 The size of numbers
- 2 Units of measurement
- 3 Arithmetic
- 3.1 Introduction
- 3.2 Arithmetic with whole numbers
- 3.3 Multiplying and dividing
- 3.4 Division
- 3.5 Order of calculations
- 3.6 Several calculations and using brackets
- 3.7 Arithmetic with decimals
- 3.11 More difficult fraction sums
- 3.12 Multiplication of fractions
- 3.14 More division with fractions
- 3.15 Mixed numbers
- 3.16 Arithmetic with negative numbers
- 3.17 Addition of negative numbers
- 3.18 Subtraction of negative numbers

- 4 OpenMark quiz
- Acknowledgements

# MU120_4M1: Numbers, units and arithmetic

## Introduction

This unit will help you to revise whole numbers, decimals and fractions, both positive and negative. You should know when and how to add, subtract, multiply and divide. Although you may have a calculator, you still need to do simple calculations in your head or on paper. Such calculations could be to estimate the size of an answer, as a check for your calculator work.

This unit is from our archive and is an adapted extract from Open mathematics (MU120) which is no longer taught by The Open University. If you want to study formally with us, you may wish to explore other courses we offer in this subject area [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] .

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## Archive content

This is an extract 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 course units or view the range of currently available OU Mathematics Education courses.