# 7.13 Units of capacity

Lesson

## Ideas

How can we  estimate capacity  ?

### Examples

#### Example 1

Choose the best estimate for the capacity of a tea cup.

A
250 millilitres
B
1 litre
C
500 millimetres
Worked Solution
Create a strategy

Use the table of examples below to compare the capacity of a tea cup.

Apply the idea

Based on the table, the juice box has a volume of 250 \text{ mL}. So the best estimate for the capacity of a tea cup is 250 \text{ mL} because a juice box and a tea cup are similar in size. So, the correct answer is A.

Idea summary

We often use millilitres \text{(mL)} and litres \text{(L)} to measure the capacity of liquids.

We can use capacities of known containers to estimate the capacities of other containers.

## Units of capacity

How do we know which unit of capacity to use?

### Examples

#### Example 2

Choose the most appropriate unit of measure for finding the amount of water in a clothes washing machine.

A
Millilitres
B
Litres
Worked Solution
Create a strategy

Apply the idea

A carton of juice is bigger than a glass of juice, so it is closer to the amount of water in a washing machine. So we should also use litres for finding the amount of water in a washing machine.

Idea summary

A millilitre is about the size of a drop of water.

A litre is about the size of a milk carton.

### Outcomes

#### MA3-11MG

selects and uses the appropriate unit to estimate, measure and calculate volumes and capacities, and converts between units of capacity