1. Introduction to Ratio
Monday, 15 April 2019

2. “There are twice as many boys as there are girls in this class”
Ratio is a method is which we can compare two or more quantities.
Example
If a class of 30 pupils contained 20 boys and 10 girls, the we could say
“There are twice as many boys as there are girls in this class”
The same information can be written as a ratio
Number of boys to girls = 2 to 1 {20 to 10 in its simplest form}
The ratio 2 to 1 is usually written
2 : 1
Hence 20 : 10 is equivalent to 2 : 1 in its simplest form

3. Example
Write each of the following ratios in their simplest form
9 : 6
40 : 10
15 : 35
10 : 15
16 : 24
21 : 9
8 : 14
50 : 80
45 : 63
24 : 36

4. Example
Express the following ratios in their simplest form
12 : 3
5 : 25
£450 : £200
£20 : £15
2 hours : 15 minutes
£3 : 50 pence
30 minutes : 1 hours

5. Example
Burnley scored 32 goals this season. United scores 24 goals.
What is the ratio of their scores, in its simplest form?

6. Example
Adam has £35 spending money where as Brian has £20.
What is the ratio of their spending money in its simplest form?

7. Example
Michael, Ian and Tom are aged 12, 8 and 16 years of age, respectively.
Write down the ratio of their ages.