Half of three and 5/8 inches: one and 5/16 plus 8/16: one and 13/16. Boom.
That’s faster than dividing decimals in your head.
It’s a useful system for residential construction, fast and accurate within about 0.031 inch. That kind of construction is done on four foot modules. Everything is marked right on the tape measure.
The only time I use a calculator is to find the spacing to make an integral number of clapboards span a window. And, I have a construction calculator that works in feet, inches, and fractions, if I need to calculate stairs or something fancy.
For cabinetmaking, either system is fine.
For machining, I prefer metric, when the equipment can handle it. Otherwise, just use decimal inches, no feet, and keep your calculator handy.
so, for conversations sake, this is a number that is made to fit nicely with imperial fractions, however, 3.625/2 is 1.5+.3125 or 1.8125.
In reality, the problem would actually be 9.2 or 9.3 CM depending on how you're rounding and what you're building. And that would be 4.6 CM and the simplicity of that isn't even close.
I've run a huge number of construction crews of all stripes and, on one crew over half of my crew came from a metric using country. I found out of about 25 people, it was substantially easier to convert my crew to metric than imperial because it's way simpler.
As for myself, I'll work in what ever tape measure I have on hand but the idea that the fractions are simpler is objectively wrong. It may feel that way because you started there, but having converted more than one crew to metric to cutdown on waste from miscuts and miscommunications I can tell you that attempts to switch crews to imperial for the same reason is pretty rough.
That’s faster than dividing decimals in your head.
It’s a useful system for residential construction, fast and accurate within about 0.031 inch. That kind of construction is done on four foot modules. Everything is marked right on the tape measure.
The only time I use a calculator is to find the spacing to make an integral number of clapboards span a window. And, I have a construction calculator that works in feet, inches, and fractions, if I need to calculate stairs or something fancy.
For cabinetmaking, either system is fine.
For machining, I prefer metric, when the equipment can handle it. Otherwise, just use decimal inches, no feet, and keep your calculator handy.