The idea, step by step
Choose a unit
You can use a small block to measure a pencil. The block is your unit.
Use blocks that are all the same size. Start at one end of the pencil and place the blocks in a row.
Make a neat measuring row
The blocks must touch end to end. Do not leave gaps or put one block on top of another.
Count the blocks. Say both the number and the unit, such as six blocks long.
A common trap
Any six blocks make a fair length measure, even if some are bigger.
Instead: Equal units are needed. Mixing sizes makes the count hard to compare.
See the thinking
A pencil in blocks
How long is the pencil in the picture?
- The equal blocks touch and line up with both ends.
- Count the six blocks.
A smaller unit
A card is 4 large blocks long. When Sam uses smaller blocks, will Sam usually need more blocks or fewer blocks?
- Each smaller block covers less of the card.
- More small blocks are needed to cover the same length.
Check your understanding
A leaf matches a row of 5 equal blocks with no gaps. How long is it?
Show answer
5 blocks long.
Each block is one unit, so count five units.
Your turn
6 questions · Work at your own pace.
Read the questions online
- How many blocks long is the pictured pencil?
- A toy car matches 4 equal blocks. Write its length.
- Which row measures fairly: blocks touching, or blocks with gaps?
- A ribbon is 7 blocks long. A card is 5 of the same blocks long. Which is longer?
- Mia measures with big blocks. Ari measures the same object with little blocks. Must their counts be the same?
- Measure a book edge using identical safe objects. Draw your measuring row and record the length.
Read the worked solutions
- How many blocks long is the pictured pencil?
Count each equal block once.
6 blocks - A toy car matches 4 equal blocks. Write its length.
Include the unit blocks.
4 blocks long. - Which row measures fairly: blocks touching, or blocks with gaps?
Gaps are not measured units.
Blocks touching. - A ribbon is 7 blocks long. A card is 5 of the same blocks long. Which is longer?
Seven equal units cover more length than five.
The ribbon. - Mia measures with big blocks. Ari measures the same object with little blocks. Must their counts be the same?
Different-sized units can give different counts for the same length.
No. - Measure a book edge using identical safe objects. Draw your measuring row and record the length.
Check that there are no gaps or overlaps.
Answers vary: equal units touch from one end to the other; the count and unit are recorded.
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 ↗