You can convert any centimeter measurement to millimeters by remembering that there are 10 millimeters in 1 centimeter. Anytime you need to convert from centimeters to millimeters, simply multiply the centimeter value by 10.
- Set up the conversion
One centimeter is equal to 10 millimeters. On a sheet of paper, write this conversion as 10 millimeters/1 centimeter.
- Write out the variables
Write down 25 centimeters as a fraction, since the conversion factor is written as a fraction. Write this fraction as 25 centimeters/1.
- Multiply the conversion factor by 25
Multiply 25 centimeters/1 x 10 millimeters/1 centimeter. The centimeter units will cancel out, and the final answer is 25 x 10, which equals 250 millimeters.