# Compare objects by capacity

Lesson

You may have learned about estimating and measuring capacity. Capacity is a word to describe how much something holds. We often use this when we think about containers.

## Comparing objects using capacity

Now we will look at comparing objects by their capacity. To compare objects we look at how much they will hold, make sure they are in the same measurement unit (such as litres) and then decide which is larger and which is smaller.

Watch this video to learn about comparing objects by their capacity.

Try these questions for yourself.

#### Worked examples

##### Question 1

Look at the two boxes and their capacities.

 Box 1 Box 2 Capacity $=$=$25$25 L Capacity $=$=$50$50 L
1. Which box is bigger?

Box 2

A

Box 1

B

Box 2

A

Box 1

B

##### Question 2

Look at the picture showing three measuring cylinders.

1. Which cylinder has the greatest capacity?

Cylinder B

A

Cylinder C

B

Cylinder A

C

Cylinder B

A

Cylinder C

B

Cylinder A

C
2. Which cylinder has the least capacity?

Cylinder B

A

Cylinder A

B

Cylinder C

C

Cylinder B

A

Cylinder A

B

Cylinder C

C
3. Which cylinder has the capacity closest to $600$600 mL?

Cylinder C

A

Cylinder A

B

Cylinder B

C

Cylinder C

A

Cylinder A

B

Cylinder B

C

## Working with capacities

We can use our mathematical knowledge to work with capacities. For example, if we have three jugs that each hold $4$4 litres, we can work out three lots of four ($3\times4$3×4) to find the total capacity. $3\times4=12$3×4=12, so the jugs can hold $12$12 litres altogether.

Now try these questions for yourself.

#### Worked examples

##### Question 3

Here is a list of the capacities of three different shaped ice cubes.

Type Capacity (mL)
Star $13$13
Circle $17$17
Square $18$18
1. Which ice cube holds the most?

The square shaped ice cube.

A

The circle shaped ice cube.

B

The star shaped ice cube.

C

The square shaped ice cube.

A

The circle shaped ice cube.

B

The star shaped ice cube.

C
2. If three of each ice cube was made, which would take the least amount of water to make?

Three square shaped ice cubes.

A

Three circle shaped ice cubes.

B

Three star shaped ice cubes.

C

Three square shaped ice cubes.

A

Three circle shaped ice cubes.

B

Three star shaped ice cubes.

C

##### Question 4

Ryan has some friends coming over and wants to make some fruit punch for them to drink.

In his kitchen then are three jugs with the following capacities:

• Jug 1 = $490$490 mL
• Jug 2 = $780$780 mL
• Jug 3 = $410$410 mL
1. If he wanted to make $760$760 mL of fruit punch, which jug should Ryan choose?

Jug 1

A

Jug 2

B

Jug 3

C

Jug 1

A

Jug 2

B

Jug 3

C

Remember!
• The capacity of an object is how much it can hold.
• To compare capacities, look at their total capacity (make sure they are in the same measuring unit), then compare them.
• If you have more than one of a container, use multiplication to work out the total capacity.

### Outcomes

#### GM2-1

Create and use appropriate units and devices to measure length, area, volume and capacity, weight (mass), turn (angle), temperature, and time.

#### GM2-2

Partition and/or combine like measures and communicate them, using numbers and units.