These D100's are HUGE and much easier to read than it seems.  The roll is the number on the flat side facing straight up and once you see it, you'll be able to easily find the number each time.

A 100-sided die, or D100, invented by Lou Zocchi in 1985, is sometimes called a Zocchihedron or "Zocchi's Golfball." Rather than being a true polyhedron, it is more like a ball with 100 flattened planes and is designed to handle percentage rolls in games, particularly in role-playing games.