G S Rehill's Interactive Maths Software Series - "Building a Strong Foundation in Mathematics" from mathsteacher.com.au.

Order a 12-month Year 7 Interactive Maths software Homework Licence for only $19.95. Order a 12-month Year 8 Interactive Maths software Homework Licence for only $19.95. Order a 12-month Year 9 Interactive Maths software Homework Licence for only $19.95. Order a 12-month Year 10 Interactive Maths software Homework Licence for only $19.95.

Year 10 Interactive Maths - Second Edition


Ratios

Ratios are used in concentration of solutions, drug dosages, similar figures, gearing, mechanical advantage and debt versus capital finance. Similar figures are widely used in the building industry, and knowledge of ratios is essential to understand the concept of similar figures.


A ratio is a comparison between two or more like quantities in the same units.

This suggests that a ratio can be simplified by dividing (or multiplying) its terms by the same number.

Note:

The ratio 1 : 2 is read as '1 to 2' or '1 is to 2'.


Simplification of Ratios

Example 1

Express the ratio 6 : 9 in its simplest form.

Solution:

Note:

The ratio 2 : 3 is in its simplest form since the numbers 2 and 3 have no common factor.


Scale Factor

If the ratio is expressed in the form 1 : n, then n is called the scale factor.

E.g.  10 : 100 = 1 : 10

So, 10 is the scale factor.


Equivalent Ratios

Clearly, 5 : 20 = 1 : 4

We say that 5 : 20 and 1 : 4 are equivalent.

In general:

Multiplying both terms of the ratio a : b by the same number, c, results in the equivalent ratio ac : bc.


Key Terms

ratio, terms of a ratio, simplest form of a ratio, scale factor, equivalent ratio


| Home Page | Order Maths Software | About the Series | Maths Software Tutorials |
| Year 7 Maths Software | Year 8 Maths Software | Year 9 Maths Software | Year 10 Maths Software |
| Homework Software | Tutor Software | Maths Software Platform | Trial Maths Software |
| Feedback | About mathsteacher.com.au | Terms and Conditions | Our Policies | Links | Contact |

Copyright © 2000-2022 mathsteacher.com Pty Ltd.  All rights reserved.
Australian Business Number 53 056 217 611

Copyright instructions for educational institutions

Please read the Terms and Conditions of Use of this Website and our Privacy and Other Policies.
If you experience difficulties when using this Website, tell us through the feedback form or by phoning the contact telephone number.