Answer: 10 centimeters
To answer this question you need to understand the metric system scale. In metric system 1 centimeter is equal to 10 millimeters or 1/100 meter. This means the equation looks like
1 centimeter= 10 millimeter
After that, you only need to convert the unit. Then 100 millimeters would be:
100 millimeter x 1centimeter/ 10 millimeter = 10 centimeters.