/diy/ - Do It Yourself

>>2615991

>>2596699
>this doesn't explain why measuring a third of an inch is not easy.
It is. See pic.

>so why is an inch 2,54cm and not 3 barleycorns
It's both.

>but that doesn't appear to be an issue
Because both units, despite being based on naturally variable things, have been precisely defined based on physical constants.

>what is 77 divided by 12?
77/12, obviously. That particular conversion is not something that comes up in practical use, so the system was not scaled with that in mind. Actually-common conversions, like partitioning a gallon into units suited for drinking, or measuring ingredients for a recipe, use nicer conversions.