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Australia
Year 4

9.08 Measure and estimate capacity

Lesson

Are you ready?

Can you choose the appropriate unit to  measure capacity  ?

Examples

Example 1

What is the best capacity unit to measure a cup of coffee?

A cup of coffee.
A
mL
B
L
Worked Solution
Create a strategy

Use the table of examples below to help you.

ObjectBest unit
Large drop of waterMillilitre
Jug of milkLitre
Apply the idea

A cup of coffee has a small amount of liquid compared to a jug of milk.

So the correct answer is A.

Idea summary

It is useful to know the capacity of some common objects so that we can estimate the capacity of new objects.

Measure capacity

How can we measure capacity?

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Examples

Example 2

This vase was filled with water and then the water was poured into this measuring cup to find the vase’s capacity. What was the capacity of water in the vase?

This image shows a vase and a measuring cup filled with 1600 millilitres of water.
Worked Solution
Create a strategy

Use the fact that the water in the measuring cup is equal to the amount of water in the vase.

Apply the idea

Based on the cup's markings, the water volume is 1600 millilitres.

Idea summary

If we have a measuring jug, we can fill a container, then pour it into a measuring jug to find out how much liquid it holds, its capacity.

Estimate capacity

This video uses some everyday objects to estimate capacity.

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Examples

Example 3

Choose the best estimate for the capacity of a rainwater tank.

A
10 litres
B
100 litres
C
100 millilitres
Worked Solution
Create a strategy

Use the table of examples below to compare the capacity of a rainwater tank.

ObjectVolume
\text{Milk carton}100 \text{ mL}
\text{Rubbish bin}10 \text{ L}
\text{Garden shed}100 \text{ L}
Apply the idea

Based on the table, the garden shed has a volume of 100 L. So the best estimate for the capacity of a rainwater tank is 100 L because a a rainwater tank and a garden shed are mostly similar in size. So, the correct answer is B.

Idea summary

If we have a measuring jug, we can fill a container, then pour it into a measuring jug to find out how much liquid it holds, its capacity. We often use millilitres (mL) and litres (L) to measure the capacity of liquids.

Outcomes

AC9M4M01

interpret unmarked and partial units when measuring and comparing attributes of length, mass, capacity, duration and temperature, using scaled and digital instruments and appropriate units

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