Converting between mm, cm and m
Units and sizes:
Units:
mm = millimetre
cm = centimetre
m = metre
Sizes:
10 mm = 1 cm
1 mm = 0.1 cm
100 cm = 1 m
1 cm = 0.01 m
1000 mm = 1 m
1 mm = 0.001 m
Scale:
Order of sizes (from the smallest on the left to the largest on the right):
mm, cm and m
(1 cm is 10 times bigger than 1 mm. 1 metre is 100 times bigger than
1 cm. 1 metre is 1000 times bigger than 1 mm)
Rules for converting between units of mm, cm and m:
•
•
•
If you are changing from cm to mm: x 10.
If you are changing from m to cm: x 100.
If you are changing from m to mm: x 1000.
•
•
•
If you are changing from mm to cm: ÷ 10.
If you are changing from cm to m: ÷ 100.
If you are changing from mm to m: ÷ 1000.
© Copyright IntelliLearn Pty Ltd 2012. All rights reserved
Some Worked Examples
For simplicity in the examples below the cancelling of units
demonstrating how the final unit is arrived at has not been shown.
If you wish to learn how to cancel units please refer to the included
video lectures.
Example
Change 3.5 cm to mm
1.
Since you are changing from cm to mm multiply by 10:
3.5 cm = 3.5 x 10 mm
Using a calculator:
To solve this using a calculator enter:
3.5 x 10 =
which gives an answer of 35.
3.5 cm = 35 mm
Without using a calculator:
3.5 x 10
Since 10 has 1 zero move the decimal point 1 place to the right.
This jump moves it from between the 3 and the 5 to immediately
after the 5:
35.
3.5 cm = 35 mm
© Copyright IntelliLearn Pty Ltd 2012. All rights reserved
Example
Change 50 mm to cm
1.
Since you are changing from mm to cm divide by 10:
50 mm = 50 ÷ 10 cm
= 5 cm
!
Example
Change 267 mm to cm
1.
Since you are changing from mm to cm divide by 10:
267 mm = 267 ÷ 10 cm
= 26.7 cm
!
Example
Convert 36.8 cm to mm
1.
Since you are changing from cm to mm multiply by 10:
36.8 cm = 36.8 "10 mm
= 368 mm
!
Example
Change 156 cm to m
1.
Since you are changing from cm to m divide by 100:
156 cm = 156 ÷ 100 m
= 1.56 m
!
© Copyright IntelliLearn Pty Ltd 2012. All rights reserved
Example
Change 0.873 m to cm
1.
Since you are changing from m to cm multiply by 100:
0.873 m = 0.873 "100 cm
= 87.3 cm
!
Example
Change 3 mm to cm
1.
Since you are changing from mm to cm divide by 10:
3 mm = 3 ÷ 10 cm
= 0.3 cm
!
© Copyright IntelliLearn Pty Ltd 2012. All rights reserved