**Definitions:**

**Centimeter** (abbreviation: **cm**): is a unit of length in the SI metric system, equal to one hundredth of a metre, centi being the prefix for a factor of 1/100. The centimetre was the base unit of length in the now deprecated centimetre–gram–second (CGS) system of units.

**Millimeter** (abbreviation: **mm**): is a unit of length in the SI metric system, equal to one thousandth of a metre. Therefore, there are thousand millimetres in a metre and ten millimetres in a centimetre.

## How to Convert Centimeters to Millimeters

*Example: How many millimeters are equivalent to 42.58 centimeters?*

As;

1 centimeters = 10 millimeters

42.58 centimeters = Y millimeters

Assuming Y is the answer, and by criss-cross principle;

Y equals 42.58 times 10 over 1

(i.e.) Y = 42.58 * 10 / 1 = 425.8 millimeters

Answer is: 425.8 millimeters are equivalent to 42.58 centimeters.

*Practice Question: Convert the following units into mm:*

N.B.: After working out the answer to each of the next questions, click adjacent button to see the correct answer.

( i ) 90.54 cm

( ii ) 44.58 cm

( iii ) 21.52 cm