Steel rulers beat plastic for math class

A stainless steel ruler with etched markings is the answer. No more squinting at a blank strip of plastic halfway through the semester.

Plastic rulers are the problem. The markings are usually printed on top, so they rub off after a few weeks in a pencil case. And plastic snaps if you look at it wrong. Steel rulers bend occasionally, but they don’t shatter, and they stay straight enough for graph paper and geometry work.

The key is the markings. Look for “etched” or “engraved” graduations — the lines are actually cut into the metal, so they can’t wear away. Avoid anything that says “printed” or “silk-screened”