The same pencil can be 8 small cubes or 4 big blocks.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
The pencil did not change
Only the unit changed. Bigger units mean you need fewer of them.
That is why you must always say the unit. "8" alone does not tell anyone anything.
Bigger unit, smaller number
The length did not change. Big units fill it in fewer steps, so the count is lower. That is why the unit has to be said.
You can only compare the same units
Eight paperclips against four cubes tells you nothing until you know which is longer, a clip or a cube.
Step 2: Try It Yourself
Tap and try it out.
Measured in small cubes
8
Measured in big blocks
4
Step 3: Watch an Example
One step at a time.
Watch Mia Measure Twice
Mia measures one ribbon two different ways.
- Step 1
With small cubes she counts 8.
Step 4: Your Turn
Practice makes it stick.
Two Rulers
Problem 1 of 1
A desk is 10 small cubes long. Measured in big blocks, will the number be bigger or smaller?
Think It Through
The object stays the same. Only the unit changes.
1 of 1
If you swap to smaller units, does the number go up or down?
Step 5: Quick Check
Show what you know.
Question 1 of 2
Why must you say which unit you used?
Question 2 of 2
A rope is 6 big blocks. In small cubes, would the number be more than 6?
What You Learned
- The same thing can give two different numbers.
- Bigger units mean a smaller count.
- Always say which unit you used.