Simplify 1.5m : 30cm

Does this means like 1.5 meter is equal to 30cm in for example in an miniature build?

if in real life you measure 1.5 meter in total, you can transfer this into a miniture build which makes it 30cm in your build. If you measure the length of a car by 3m, and you want to make a miniature build of it, you can do 30cm x 2 (because 3m is 2x 1.5) and in a miniature build you have to make you build 60cm in length

I hope this makes it clear for you.