To measure, lay cubes along the object and count them.
Step 1: Let's Learn
Read it, or press Listen and follow the words.
Watch out for gaps
If you leave spaces between the cubes, you will count too few.
Measured badly
6
Look closely at the cubes. They have gaps between them, so this measurement is wrong.
Length
And overlaps
If the cubes sit on top of each other, you will count too many.
Measured badly
6
Look closely at the cubes. They have been laid on top of each other, so this measurement is wrong.
Length
Why gaps and overlaps ruin it
A gap means length you never counted. An overlap means length you counted twice. Either way the number is wrong.
What the number means
Six cubes long does not mean six. It means six of that cube. The unit is part of the answer.
Step 2: Try It Yourself
Count the cubes along the bar.
Pencil
7
Step 3: Watch an Example
One step at a time.
Watch Leo Measure
Leo measures a pencil with cubes.
- Step 1
He starts the first cube exactly at the end of the pencil.
Step 4: Your Turn
Practice makes it stick.
Measuring a Book
Problem 1 of 1
Ana lays 8 cubes end to end along a book with no gaps. How long is the book?
Spot the Mistake
Ben measured with gaps between his cubes.
Ben left gaps between his cubes. Will his answer be too big or too small?
Step 5: Quick Check
Show what you know.
Question 1 of 2
A stick takes 6 cubes laid end to end. How long is it?
Question 2 of 2
What must be true about the cubes you measure with?
What You Learned
- Lay the cubes end to end.
- No gaps and no overlaps.
- Then count them.