New
New
Lesson 3 of 10
New
New
- Year 3
Converting between metres and centimetres
I can convert between metres and centimetres.
Lesson details
Key learning points
- Using the known fact that 100 cm are equivalent to 1 m can help us convert between cm and m.
- Partitioning and using the relationship between 1 m and 100 cm can help us convert between cm, and m and cm.
- It is always important to estimate so you know if your answer is near to the real value.
Keywords
Equivalent - When something is equivalent, it is equal in value.
Convert - When we convert, we change the unit of measurement between metres and centimetres, but the value remains the same.
Common misconception
Some children may think that 300 cm is bigger than 3 m because 300 is a bigger number than 3.
1 m is equivalent to 100 cm. So 3 m is equivalent to 300 cm. 3 m and 300 cm are equal in length or height.
Show the equivalence between 1 m and 100 cm practically where possible e.g. using a metre ruler. Lots of chanting to help children recall the key fact that 100 cm is equal to 1 m.
Teacher tip
Licence
This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Which unit would you use to measure the length of a whale?
Which unit would you use to measure the length of a whale?
mm
cm
kg
Q2.Which unit would you use to measure the length of a book?
Which unit would you use to measure the length of a book?
mm
m
kg
Q3.What is the length of this toy car?
What is the length of this toy car?
Q4.What is the length of this twig?
What is the length of this twig?
7 cm
12 cm
Q5.Starting with the tallest, place these measurements in order of height.
Starting with the tallest, place these measurements in order of height.
Q6.What is the height of this pebble?
What is the height of this pebble?
7 cm
9 cm
Assessment exit quiz
6 Questions
Q1.When we change the unit of measurement between metres and centimetres, but the value remains the same, it is known as
When we change the unit of measurement between metres and centimetres, but the value remains the same, it is known as
equivalent
Q2.If one metre is equal to 100 cm, how many cm are 3 metres equal to?
If one metre is equal to 100 cm, how many cm are 3 metres equal to?
Q3.Convert the height of this giraffe from metres to centimetres.
Convert the height of this giraffe from metres to centimetres.
5 cm
50 cm
Q4.Match the lengths to their equivalent length.
Match the lengths to their equivalent length.
Q5.Starting with the shortest, put these measurements in order of length.
Starting with the shortest, put these measurements in order of length.
Q6.A piece of ribbon is 4 m 90 cm long. 300 cm is cut away from the ribbon. What is the length of the ribbon now?
A piece of ribbon is 4 m 90 cm long. 300 cm is cut away from the ribbon. What is the length of the ribbon now?
