Question

change 2.0mm into meter

Answer 1

10mm=1cm
1mm=0.1cm
0.1cm=0.001m

Answer 2

$1 \: metre = 1000 \: mm \\ then \\ \: \: \: \: 1 \: mm = \frac{1}{1000}m \\ atq \: \\ \: \: \: \: 2.0 \: mm = \frac{2}{1000} \\ \: \: \: \: \: 2.0mm = \frac{1}{500} m \\ ans. \frac{1}{500} \: metre$
That is your Answer