A centimeter (cm) is a unit of length in the metric system, and it is equal to 10 millimeters (mm). This is because the prefix ‘centi-‘ means one hundredth, so one centimeter is one hundredth of a meter, while a millimeter is one thousandth of a meter.
To put it simply, if you take one centimeter and break it down, you will find that it consists of 10 millimeter segments. Therefore, whenever you need to convert centimeters to millimeters, you can easily multiply the number of centimeters by 10.