New
New
Year 3
Converting between centimetres and millimetres
I can convert between centimetres and millimetres
New
New
Year 3
Converting between centimetres and millimetres
I can convert between centimetres and millimetres
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Lesson details
Key learning points
- To convert between cm and mm, we can use the relationship between 1 cm and 10 mm.
- To convert between mm, and cm and mm, we can use partitioning.
- Estimating the length or height of an object helps us to decide which unit to use when measuring.
Keywords
Equivalent - When something is equivalent, it is equal in value.
Convert - When we can convert, we change the unit of measurement between millimetres and centimetres but the value remains the same.
Common misconception
E.g. 30 mm is not equivalent to 3 cm because 30 is a larger number.
10 mm are equivalent to 1 cm. Millimetres are smaller than centimetres and 10 mm are needed to make an equivalent length to 1 cm.
This lesson should be done as practically as possible. Ensure the children have concrete experience of what 1 mm, 10 mm and 1 cm look like. It is not necessary to relate the learning to the 10 times-table but can be discussed if a child spots it.
Teacher tip
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Starter quiz
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6 Questions
Q1.
What is the length of this ribbon?
Q2.
There are in 1 m.
1 cm
10 cm
10 mm
100 mm
Q3.
Starting with the tallest, order these measurements of height.
Q4.
What is the length of this ribbon?
3 cm
10 cm
Q5.
What is the length of this pencil?
5 cm
5 cm 40 mm
5 mm 4 mm
6 mm
Q6.
By partitioning, match the whole number to its parts.
10 and 8
20 and 7
20 and 9
30 and 1
10 and 3
70 and 2
Exit quiz
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6 Questions
Q1.
When we change the unit of measurement between millimetres and centimetres, we .
equivalent
Q2.
Convert the length of this leaf from cm into mm.
4 mm
400 mm
Q3.
Which pebble is longer?
The green pebble is longer.
The brown pebble is longer.
Q4.
Match the given lengths in cm and mm to their mm equivalent.
11 mm
35 mm
53 mm
68 mm
69 mm
79 mm
Q5.
Which mouse is taller and by how much?
The grey mouse is taller by 1 cm.
The white mouse is taller by 1 cm.
The white mouse is taller by 1 mm.
Q6.
Starting with the tallest, put these lengths into order.