> I would love to hear from someone who does carpentry (or some craft-like equivalent) with the metric system- specifically what kind of ruler/tape they use and

> I would love to hear from someone who does carpentry (or some craft-like equivalent) with the metric system- specifically what kind of ruler/tape they use and whether it has a special 1/3 and 2/3 mark on it (since you don't want to have to eyeball 0.33333....) or if they just avoid dividing things by three altogether. I would love to hear from someone that uses the imperial system how they determine exactly 1/3 of 10 inches and how they eyeball 1/3 of 5/6 of an inch.... My point is it is easy to find measurement scenarios that would make life a little harder for either system. 12cm (metric) for example is trivial to divide into 1/3, 2/3, 1/2, 1/4, 1/6 etc etc. 4.72 inches (imperial equivalent of 12cm) would be harder to do. Besides there are very easy geometric methods to divide a line exactly into any number of equal parts, even if you do not know its actual length precisely.