## Changing Units

To change units, try drawing a diagram. Suppose you want to change
$50cm^2$
into
$m^2$
, which the usual unit. May people would divide by 100 because there are 100 centimetres in a metre.
THIS IS WRONG! Draw a recjangle with sides labelled in cm that multiply to give 50.

Change each side into metres, then multiply to give the area in
$m^2$