Question

Why not we convert 9cm =9*100cm=9m if we know 100cm=1m proof me wrong with a good reason

Answer 1

First of all dear you are wrong we convert 9cm I'm Meter by dividing 9/100 not by multipleying it so 9 = 0.09m.
hope this helps you...:)

Answer 2

for converting cm to m you have to divide it with hundred
e.g
$\frac{9}{100} = 0.09$
9cm=0.09m