The idea, step by step
Start at the same place
Length tells us how far something reaches from one end to the other. Put two strips beside each other.
Line up one end. The strip that reaches farther is longer. The other strip is shorter.
Turn and check
A strip does not get longer when you turn it. Straighten a bent string before comparing it with another length.
If both ends match after you line up the starts, the strips have the same length.
A common trap
The object whose end is farther right must be longer.
Instead: First line up the starting ends. A short object can look long if it starts farther along.
See the thinking
Compare two strips
Look at strips A and B. Which strip is longer?
- Both strips start at the dashed line.
- Strip A reaches farther to the right.
Check an unfair start
One ribbon starts farther along the table. It seems to end farther away. Can you say it is longer yet?
- The starting ends are not lined up.
- Move the ribbons so that one end matches. Then compare the other ends.
Check your understanding
Two straight strips start together and end together. What can you say?
Show answer
They have the same length.
Both distances from start to end match.
Your turn
6 questions · Work at your own pace.
Read the questions online
- Use the picture. Which strip is shorter?
- A straw is longer than a spoon. Which is shorter?
- Two strings have matching starts and matching ends. Finish: They have the ___ length.
- Two pencils start in different places. What should you do before comparing their lengths?
- Does turning a pencil around change its length?
- Find two safe objects. Draw them with one end lined up. Label the longer object.
Read the worked solutions
- Use the picture. Which strip is shorter?
The starts match.
B does not reach as far.
B - A straw is longer than a spoon. Which is shorter?
Longer and shorter compare the same pair.
The spoon. - Two strings have matching starts and matching ends. Finish: They have the ___ length.
Both ends match.
same - Two pencils start in different places. What should you do before comparing their lengths?
Use the same starting place.
Line up one end of the pencils. - Does turning a pencil around change its length?
It is still the same pencil from end to end.
No. - Find two safe objects. Draw them with one end lined up. Label the longer object.
Compare actual objects after lining up one end.
Answers vary: the drawing lines up one end and correctly labels the object reaching farther.
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 ↗