[rhelz]

> now you can't represent 1/10

This is why 12-inch rulers commonly have the inches divided into 10 inches.

There is a line on that ruler for 1/2, 1/3, 1/4, 1/5, 1/6, 1/8, and 1/10 of a foot. Uh, and 1/12th of a foot too, of course :-)

cf. with a 10-cm ruler, each cm divided into 10 mm. You've got a line for 1/2, 1/4, 1/5, 1/10, and 1/25, and 1/100th. That's it.