[bluGill]

Depends. they are designed so the whole units are easy for the common things you do with that size. this is a common case for things will still do today like we did 200 years ago (like build houses). But even in those areas a lot of things are not round units.

When things are not nice round units though both systems are equally hard. This is common in the modern world where we do a lot of things impossible 200 years ago.

in reality you almost never calculate on the job. You measure what is on the print and anything not on the print is figured out 'when you get there' by measuring the space left when you get there - which also corrects for previous measurement errors

[taeric]

Related to this, I find the "default to round numbers" influence interesting on things like minimal speeds. Where my understanding is many metric based systems have a smallest max speed of 30km/h. Which is between the common 15 and 20 that I'm used to seeing as the lowest.

I tried asking on a forum once on how this impacted default room sizes. I see standard ceiling size in the US is moving to 9 feet. I am assuming places on metric would not standardize on that number, but curious if they would just stick to the nearest half, or go to the nearest whole meter. (I "tried" asking, as people seemed to think that you would just design the room to be 2.74 meters and call it a day. That strikes me as very unlikely, as design tools really love "snap to grid.")