I'm wondering, because i'm doing this: 30% of 360m

I already know for example: 6%of $20 = 6/100 x 20/1

= 120/100

= $1.20

but when i'm doing: 30% of 360m = 30/100 x 360/1(is that right? were mean't to be simplifying i think)

But when i multiply 30 by 360 i get: 10'800

How would i lay out my question! Because i'v converted the percentage and quantity to fraction.

Multiplyed and simplifyed (i hope)

And another one i'm puzzling over is: 75% of $1240