Answer:
10 mm/cm
Step-by-step explanation:
The conversion factor always has a value of 1. It is a fraction with the numerator equal to the denominator -- only the units are different.
The numerator units are the units you're converting to: millimeters. The denominator units are the units you're converting from: centimeters.
You know that 1 cm = 10 mm, so when you arrange the fraction as described, the conversion factor you're multiplying by is ...
[tex]\boxed{\dfrac{10\,\text{mm}}{1\,\text{cm}}}[/tex]
