For people who don't get any of this, Americans use:
* Inches and fractions for "small" things: 7½ inches, 15¾
* Feet and inches for "large" things (like more than 2 feet): 6 feet 2 inches, 30 feet 7¼.
* Thousandths of an inch for tiny things: 38 thousandths, off by a 'thou.
* 1 foot 3 3/8 inches is valid but uncommon, people typically just say 15 and 3/8ths
* 5.91 inches is weird, converting from millimeters (not hundredths of a mm) you probably best round to 5 and 15/16ths which at least is on a tape measure
* 0.79 feet is just malarkey
In England we measure speed with furlongs per fortnight.
It's a rather bizarre mix of units here - the transportation systems interchangeably uses kilometers and miles, some shop owners by principle refuse to use kilograms and insist on "pounds" (without realising a "pound" is defined in law using grams and that there was like a dozen of "pounds"), fuel efficiency is measures in miles per gallon, but it's a different gallon from the one used in the US. In general, the whole units situation is nothing but a confusing dick contest.,,
As soon as various engineering and scientific disciplines started to get interconnected, it became critical to develop a common frame of reference. SI units are such frame, as they are defined based on specific physical constants rather and this would explain why the scientific world uniformly converted to SI.
You probably *could* build an atomic clock based on the notion that Cs-133 wavelength is 1" and 268/1000" but that's not very practical nor portable.
@kravietz
It doesn’t matter if you do your calculations in feet or meters, you know perfectly well no one’s suggesting to always use fractions, abandoning base 10 or decimal point numbers.
When solving a single math equation, people mix decimals, rational numbers, and symbolic placeholders for numbers however it tickles their fancy. No standards committee should force them to do otherwise, you should use the system that makes the problem solvable or easiest.
@cjd