You cannot. Inches are a measurement unit; here is no intrinsic numerical value.
28" or 2'4"
6' 3"
It is already written in numeric form!
470 = CDLXX
00610418452911
Exactly as in the question.
5,000,000
If the number is accurate to two decimal places then you write it exactly as in the question.
75 km is a good enough numeric format.
It is in numeric format. You have answered the question for yourself.
The numeric or standard format is 125,000
5'8" is as numeric as you will get. You can express the height in inches, or centimetres, or miles or microns or whatever. You will always have a number (or numbers) and the measurement units.