# Find a decimal proportion of a quantity

Lesson

All the information, techniques and strategies that you have learnt about decimals already can be used to work out decimal amounts that you may see in everyday life. If we want to find part of a quantity, we find part of a whole by using multiplication.

#### Examples

##### question 1

Evaluate: Find $0.3$0.3 of $\$20.8020.80

Think: As an equation, we would write this as $0.3\times20.80$0.3×20.80

Do: $0.3\times20.80=\$6.24$0.3×20.80=$6.24

##### question 2

Evaluate: Find $0.08$0.08 of $42$42 litres. Express your answer in millilitres

Think: As an equation, we would write this $0.08\times42$0.08×42

Do:

 $0.08\times42$0.08×42 $=$= $3.36$3.36 litres $=$= $3360$3360 millilitres
##### QUESTION 3

Find $0.7$0.7 of $22$22 litres. Write your answer as a decimal.

### Outcomes

#### NA5-3

Understand operations on fractions, decimals, percentages, and integers