Converting millimetres (mm) to metres (m), and m to mm

Sometimes you have to do calculations using quantities in both mm and m. In order to do a calculation you need to convert all the measurements to the same units.

Your calculations workbook usually converts all measurements to metres (because you’re generally working with larger measurements and it’s easier to think of a roof as being 20m long than 20 000 mm).

For more explanation and practice on multiplying and dividing by 1000 go to:

www.bbc.co.uk/skillswise/numbers/wholenumbers/multiplication/multiply10and100/

Remember 1000mm = 1 m

Check out these tables. You’ll see the pattern.

To convert millimetres (mm) to metres (m), divide the number in millimetres by 1000.

HINT: When dividing a number by 1000 move the decimal point 3 places to the LEFT, making your original number 3 times smaller.

Eg 800.0 mm ÷ 1000, move the decimal point 3 places to the left = .8 m

To convert metres (m) to millimetres (mm), multiply the number in metres by 1000.

HINT: When multiplying a number by 1000 move the decimal point 3 places to the RIGHT, making your original number 3 times larger.

Eg 0.800m × 1000, move the decimal point 3 places to the right= 800.0 mm

If you want to print this then click here