Understand the idea.
Heavy is not the same as big
Mass tells us how heavy an object is. How big something looks does not decide its mass: a small stone can be heavier than a large sponge. We need a comparison, rather than a guess from size.
You can compare small, safe objects by holding one in each hand, or use a balance. Ask an adult for help before lifting a heavy object. A balance can make the comparison easier to see.
Read a balance
On a balance, the heavier object makes its pan go down. The lighter object's pan goes up. Look for which pan is lower before you name the heavier object.
Level pans show that the objects balance. They have the same mass, even if their colours, shapes or sizes differ. If neither pan is lower, do not choose a heavier side.
See the method in action.
The lower pan
The stone pan is lower in the picture. Which object is heavier?
Worked solution
- 1
Find the lower pan.
The stone pan is lower than the sponge pan in the picture.
- 2
Use what the balance shows.
The heavier object makes its pan go down.
- 3
Compare the objects.
The stone is heavier than the sponge; the sponge is lighter than the stone.
The stone is heavier than the sponge.
A level balance
A toy and a bag of blocks make the pans level. Which has more mass?
Worked solution
- 1
Check the two pan heights.
The question says the pans are level.
- 2
Describe the balance.
Neither object pulls its pan lower than the other.
- 3
State the mass comparison.
Neither has more mass: the toy and the bag of blocks have the same mass.
Neither. They have the same mass.
Try it yourself.
Check your understanding
A pan holding a book is higher than a pan holding a box. Which object is lighter?
Show answer & reasoning
The book.
The book is lighter. Its pan is higher, while the heavier box makes the other pan lower.
Keep practising
6 worksheet questions
Read the questions online
- Use the balance picture. Which object is lighter?
- A ball and a block balance on level pans. Compare their masses.
- A small rock is heavier than a large empty cup. Is the larger object always heavier?
- The apple pan is lower than the feather pan. Complete: The apple is ___ than the feather.
- One box balances 4 identical blocks. Another box balances 6 of those blocks. Which box is heavier?
- Explain how a balance could help you choose the lighter of two toys.
Read the worked solutions
- Use the balance picture. Which object is lighter?
Its pan is higher.
The sponge. - A ball and a block balance on level pans. Compare their masses.
Level pans show equal mass.
They have the same mass. - A small rock is heavier than a large empty cup. Is the larger object always heavier?
This rock is smaller but heavier.
No. - The apple pan is lower than the feather pan. Complete: The apple is ___ than the feather.
The lower pan has more mass.
heavier - One box balances 4 identical blocks. Another box balances 6 of those blocks. Which box is heavier?
The blocks all have the same mass.
Six blocks are heavier than four blocks, so the box balancing six is heavier.
The second box. - Explain how a balance could help you choose the lighter of two toys.
Read the position of the pans, not the size of the toys.
Put one toy on each pan. The toy on the higher pan is lighter; if level, they have the same mass.
Curriculum reference & lesson scope
Australian Curriculum v9 / SA Curriculum 2026
Year 1 informal comparisons and measuring with uniform units; explanation and practical activity accompany fluency.
Official curriculum source ↗