Measuring Length up to 10 m
Primary 1 · Mathematics
Measuring Length up to 10 m
Lesson 1 of 5
10 min
Let's begin
Uwase and Mugisha find two sticks near the school gate.
Mugisha holds his stick high in the air. He says his stick is longer.
Uwase is not sure. She wants a fair way to check.
Today you will learn that fair way.
Find two sticks. A pencil and a spoon also work.
Lay them side by side on the floor.
Push both ends against the same wall.
Now look at the other ends. One thing goes further.
That one is longer. The other one is shorter.
Careful! Mugisha held his stick up high. Holding it high does not make it longer.
Only the same start line tells the truth.
Three words tell what you see.
Worked example
two ropes on the floor.
Step 1 Lay both ropes flat. Pull each one straight.
Step 2 Push both left ends against the wall.
Step 3 Look at the right ends.
Keza's rope stops first. Gatete's rope goes on further.
So Gatete's rope is longer.
Careful! A curled rope looks short. Pull it straight first.
A tall thing is long when it stands up.
Stand back to back with a friend. Your feet are the same start line!
Now a grown person looks at your heads.
One head is higher. That friend is taller.
The same rule works again: same start line first.
Tip
Same start line. Then look at the end
Stand your two things against a wall, like children in a line.
If one thing starts further along, your eyes will lie to you.
Watch: pencils on one line, then who is longer.
Do each one, then tap Show answer to check.
Two pencils start at the same line. One pencil ends further along. Which pencil is longer?
Answer: the pencil that ends further along.
Mugisha's stick starts further along the floor than Keza's stick. Can you say his stick is longer?
Answer: no. Move both ends to one line first.
Two ropes start at the wall. Both end at the same place. What do you say?
Answer: they are the same length.
A rope is longer than a stick. The stick is longer than a pencil. Which one is the longest?
Answer: the rope. It beats the stick, and the stick beats the pencil.
Find two sticks outside. Line them up against a wall. Say which one is longer.
Answer: the stick whose other end goes further.
What you learned today
Quick check
Two sticks start on one line. The longer one...
