Year 7 Interactive Maths - Second Edition

Comparing Quantities

This suggests that a ratio can be simplified by dividing its terms by the same number.  Therefore:

This suggests that the terms of a ratio can be multiplied by the same number.  Therefore:

Note:

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

Simplifying Ratios

Example 1

Express the ratio 8 : 12 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.

So, 10 is the scale factor.

Equivalent Ratios

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

Key Terms

ratio, terms, simplest form, scale factor, equivalent ratios

Study Another Topic in Chapter 11: Ratios

[ Comparing Quantities ] [ Finding the Ratio of Two Quantities ] [ Spreadsheet Applications ] [ Problem Solving Unit ] [ Symbols ] [ Index ]