Question

A book is 0.33 meters long. How many millimeters long is it?

Answer 1

we know that

$1\ meter=1,000\ millimeters$

so

by proportion

Find how many millimeters are in $0.33$ meters

$\frac{1,000}{1} \frac{mm}{m} =\frac{x}{0.33} \frac{mm}{m} \\ \\x=1,000*0.33 \\ \\ x=330\ mm$

therefore

the answer is

$330\ mm$