New
New
Year 3

# Millimetres as a unit of measure and the relationship between them and cm

I can understand millimetres as a unit of measure and describe the relationship between mm and cm.

New
New
Year 3

# Millimetres as a unit of measure and the relationship between them and cm

I can understand millimetres as a unit of measure and describe the relationship between mm and cm.

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## Lesson details

### Key learning points

1. Small objects are measured in millimetres.
2. There are 10 mm in 1 cm

### Common misconception

Children may think that 10 mm are larger than 1 cm.

There are 10 mm in 1 cm. 1 cm is made up of 10 mm. 10 mm and 1 cm are equivalent in length.

### Keywords

• Millimetre - A millimetre is a standardised unit of measurement. We can abbreviate millimetre to mm.

Where possible, do this lesson practically using classroom 15 or 30 cm rulers where mm can be seen.
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

### 6 Questions

Q1.
I have a piece of ribbon that is 80 cm long. Is this ribbon shorter or longer than one metre?
longer
Q2.
Which unit would you use to measure the length of a swimming pool?
mm
cm
kg
Q3.
Match the calculation to its answer.
Correct Answer:1 x 10 = ,10

10

Correct Answer:8 x 10 = ,80

80

Correct Answer:10 x 5 = ,50

50

6 x 10

10 x 2

Correct Answer:100 = ,10 x 10

10 x 10

Q4.
What is the length of this leaf?
Correct Answer: 4 cm, four cm, for cm
Q5.
If one metre is equal to 100 cm, how many cm are 6 metres equal to?
Correct Answer: 600 cm, 600, 6 hundred, six hundred, sixhundred
Q6.
Convert the height of this house from centimetres to metres.
800 m
80 m

## Exit quiz

### 6 Questions

Q1.
Which unit of measurement is represented by the shading and arrow in this image?
Centimetres
Metres
Q2.
Which of these objects would you measure in millimetres?
Length of a football pitch.
Height of a house.
Correct answer: Width of a pencil.
Length of a desk.
Q3.
Which is smaller, one centimetre or one millimetre?
1 cm
Q4.
Is the pebble shorter or longer than 1 cm?
shorter