Question

What is the difference in mm between 3.9 cm and 4.6 cm

Answer 1

The 'difference' of something tells you that you need to subtract two numbers.
4.6 cm - 3.9 cm = 0.7cm

Because there are 10mm in a cm, you have to times 0.7cm by 10 to get the number of mm.

Therefore, 0.7cm times 10 = 70mm

Answer 2

4.6 - 3.9= .7cm which is 7mm