Understand the idea.
Choose a unit
A unit is the small length you repeat when measuring. Here, one block is one unit. Choose equal-sized blocks so each counted block adds the same amount to the measured length.
Place the first block at one end of the object. Continue in a straight row beside it. Matching the start matters: a row beginning partway along the pencil would miss some of its length.
Make a neat measuring row
Make the blocks touch end to end, with no gaps or overlaps. A gap adds space that is not a block; an overlap hides part of a block. Either would spoil the count.
When the row matches both ends, count each block once. Report the number and the unit: six blocks long. A smaller block covers less length, so more small blocks are needed for the same object.
See the method in action.
A pencil in blocks
How long is the pencil in the picture?
Worked solution
- 1
Check the measuring row.
The equal blocks touch and match both ends of the pencil.
- 2
Count each block once.
Every block represents one equal length unit.
- 3
Say the number and unit.
The pencil matches the complete row of six blocks.
The pencil is 6 blocks long.
A smaller unit
A card is 4 large blocks long. When Sam uses smaller blocks, will Sam usually need more blocks or fewer blocks?
Worked solution
- 1
Keep the card the same length.
Changing the measuring block does not change the card.
- 2
Compare one small block with one large block.
A smaller block covers less of the card each time.
- 3
Choose more blocks.
More smaller blocks are needed to cover the length that four larger blocks covered.
More blocks. The card has not changed length.
Try it yourself.
Check your understanding
A leaf matches a row of 5 equal blocks with no gaps. How long is it?
Show answer & reasoning
5 blocks long.
The leaf matches five equal touching blocks, so its length is five blocks. The word blocks tells us which unit was used.
Keep practising
6 worksheet questions
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 ↗