Understand the idea.
Three different questions
Choose the kind of measurement before counting. Length tells how long, high or wide something is. Mass tells how heavy it is. Capacity tells how much a container can hold. These answer different questions about the same object.
Choose the question before the tool
Match the tool to your question: line up ends to compare lengths, use a balance for masses, and fill containers with the same cup to compare capacities. Looking at height alone cannot tell which container holds more; width and space inside matter too.
See the method in action.
A new ribbon
Mia needs ribbon to go around a parcel. Should she think about length, mass or capacity?
Worked solution
- 1
Identify what the ribbon must do.
It must reach all the way around the parcel.
- 2
Choose the measurement that describes reach.
Length tells how long the ribbon is, so length is the measurement Mia needs.
Length.
Filling a bottle
A bottle holds 5 equal cups. A jug holds 8 of those cups. Which has the greater capacity?
Worked solution
- 1
Check the measuring cups match.
Both containers are measured with the same equal cup, making the counts comparable.
- 2
Compare their full-cup counts.
The jug takes eight of those cups while the bottle takes five.
- 3
Choose the jug.
Holding more of the same cup means the jug has greater capacity.
The jug.
Try it yourself.
Check your understanding
Which attribute tells how heavy a lunch box is?
Show answer & reasoning
Mass.
“How heavy?” asks about mass. Length describes size in a direction, and capacity describes how much a container holds.
Keep practising
6 worksheet questions
Read the questions online
- Would you measure length, mass or capacity to choose a ribbon long enough for a present?
- Would you compare length, mass or capacity to find the heavier school bag?
- Would you measure length, mass or capacity to find how much water a bucket holds?
- A jar holds 4 equal scoops of rice. A tub holds 7 of the same scoops. Which holds more?
- A toy balances with 6 equal cubes. A block balances with 9 of those cubes. Which has more mass?
- A shoe is 8 equal blocks long. A pencil is 5 of the same blocks long. Which is longer?
Read the worked solutions
- Would you measure length, mass or capacity to choose a ribbon long enough for a present?
We need to know how long the ribbon is.
Length. - Would you compare length, mass or capacity to find the heavier school bag?
Heavier and lighter describe mass.
Mass. - Would you measure length, mass or capacity to find how much water a bucket holds?
Capacity describes what fits inside.
Capacity. - A jar holds 4 equal scoops of rice. A tub holds 7 of the same scoops. Which holds more?
7 scoops is more than 4.
The tub. - A toy balances with 6 equal cubes. A block balances with 9 of those cubes. Which has more mass?
9 equal cubes have more mass than 6.
The block. - A shoe is 8 equal blocks long. A pencil is 5 of the same blocks long. Which is longer?
8 blocks is longer than 5 of the same blocks.
The shoe.
Curriculum reference & lesson scope
Australian Curriculum v9 / SA Curriculum 2026
Length, mass and capacity; uniform informal units; smaller units for accuracy; comparison.
Official curriculum source ↗