The idea, step by step
Choose the right comparison
First decide what you want to compare. Use length for how long, mass for how heavy, and capacity for how much fits inside.
A balance helps with mass. Equal blocks help with length. The same small cup helps with capacity.
Keep the comparison fair
For length, match the starting ends. When measuring, use equal units with no gaps or overlaps.
For capacity, use the same cupful each time. Compare the property you are asked about, not only how an object looks.
A common trap
The same tool can answer every measuring question.
Instead: Choose a method for the property: length, mass or capacity.
See the thinking
Fix the blocks
Four blocks have gaps between them under a pencil. Is that a fair length measure?
- The gaps are not blocks.
- Close the gaps, line up the start and check the far end.
Choose a tool
You want to know which lunchbox is heavier. Should you compare their colours or use a balance?
- The question is about mass.
- A balance compares how heavy the lunchboxes are.
Check your understanding
Two containers are measured with different-sized cups. How could you make the comparison fair?
Show answer
Measure both again with the same cup.
The unit must stay the same so the counts mean the same thing.
Your turn
6 questions · Work at your own pace.
Read the questions online
- You want the longest ribbon. What should you line up first?
- You want the lighter toy. Which tool helps: a balance or a small cup?
- You want the container that holds most. Which unit helps: equal cupfuls or pencil lengths?
- Use the picture. Which row measures fairly, A or B? Explain.
- A block row overlaps at two places. What must you fix?
- A child says a tall empty bottle holds more than a short wide bottle just because it is taller. What would you suggest?
Read the worked solutions
- You want the longest ribbon. What should you line up first?
Use a shared starting point.
One end of each ribbon. - You want the lighter toy. Which tool helps: a balance or a small cup?
Lighter describes mass.
A balance. - You want the container that holds most. Which unit helps: equal cupfuls or pencil lengths?
Cupfuls compare capacity.
Equal cupfuls. - Use the picture. Which row measures fairly, A or B? Explain.
Row A has equal units without gaps.
Row B leaves gaps between the blocks.
A. The equal blocks touch end to end. - A block row overlaps at two places. What must you fix?
Each unit should cover a new part of the length.
Place the blocks end to end without overlaps. - A child says a tall empty bottle holds more than a short wide bottle just because it is taller. What would you suggest?
Height alone does not show the total capacity.
Check by filling each with the same cup, or compare by careful pouring.
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 ↗