Help converting real to N scale

I KNOW N scale is 1/160. I’m having trouble though…math never WAS my strong subject! VBG.
How do I figure out how many “scale feet” are in an inch, say?
Like how “high” is a three INCH N scale building?
How many “scale feet” are in a “real” foot?
Over an 8 (real) foot run how HIGH will a 3% grade get my train?
HOW do I figure this stuff out…I DO have a calculator…LoL]

A 3" N scale building is 3 X 160 = 480 scale inches, divide by 12 to get 40 scale feet.
A real inch is 160 N scale inches, divide 160 by 12 to get 13 1/3 N scale feet.
A real foot is 160 scale feet.
A 3% grade means a rise of 3 inches per 100 inches. 8 real feet = 8 *12 = 96 real inches.
96 * .03 (3% expressed as decimal) = 2.88 real inches.
For other values substitute above.
Hope this helps
Paul

Thanks for the help. I guess it really IS as “simple” as I thought. I appreciate your input.
Gotta LOVE N scale!
untabubba