On the bar you see marks like on a ruler.
Every mark is one centimeter.
This is how you do it:
1. Start at the left end of the bar at 0.
2. Count the sections up to the right end.
3. Write the number down with the unit cm.
The number written in shows the answer.
Example
For parents
What does this exercise practice?
Reading lengths off a scale safely and giving them in centimeters.
Common pitfalls
Children often count the marks instead of the sections and end up with one too many. It helps to always count the gaps between them.
How to practice at home
Use a real ruler to measure pencils, books or your own hand and compare the lengths.
Related: Read the ruler, Converting Units, Comparing Measurements