How many millimeters are in 3.5 cm?

To determine how many millimeters are in 3.5 centimeters, it's essential to know the conversion factor between centimeters and millimeters. There are 10 millimeters in 1 centimeter.

To convert centimeters to millimeters, you multiply the number of centimeters by 10. In this case, 3.5 centimeters can be converted as follows:

3.5 cm × 10 mm/cm = 35 mm.

Therefore, the correct answer is that there are 35 millimeters in 3.5 centimeters. This conversion is a straightforward application of the metric system, which is based on multiples of ten, making calculations like this simple and efficient.