How do you convert cm to mm?

Hint: Here we will see how to convert the centimeter into millimeters. Before we will know what is centimeter and what is millimeter and then how to convert it into other units. Finally we conclude the required answer.

Complete step-by-step solution:
Millimeter (mm) and centimeter (cm):
$1cm = 10mm$
$1mm = 0.1cm = \dfrac{1}{{10}}cm$
Both centimeters and millimeters are derived from the meter, a measurement of distance used in the metric system. Millimeters and centimeters are separated by one tens place, which means that there are $10$ millimeters for every centimeter.
A millimeter (abbreviated as mm and sometimes spelled as millimeter) is a small unit of displacement (length/distance) in the metric system. Millimeters are used to measure very small but visible scale distances and lengths.
The metric system is based on decimals, there are $10mm$ in a centimeter and $1000mm$ in a meter. The base of the Greek root words indicates that they are hundredths (centi) and thousandths (milli) of meters. Both are the meter is the international system of units (SI) base unit of length. The corresponding unit of area is the square millimeter and the corresponding unit of volume is the cubic millimeter.
How to convert mm to cm?
To convert mm to cm divides the number of mm by $10$ to get the number of cm.
Example: $35mm = 35 \div 10 = 3.5cm$
How to convert cm to mm?
To convert centimeters to millimeters, multiply by $10$ centimeters $ \times $ $10 = $ millimeters.
Example: $40cm = 40 \times 10 = 400mm$
Centimeter to millimeter conversion table:


Note: If you can’t remember that $1cm = 10mm$, you can always use the definitions of Milli Centi:
Milli $ = {10^{ - 3}}$ so $1mm = {10^{ - 3}}m$
Centi $ = {10^{ - 2}}$so $1cm = {10^{ - 2}}m$
Then you can convert “cm” to “m” to “mm”. It is an extra step but it always works.