With the advent of CAD systems, fewer and fewer people are solving shop math problems the old fashioned way. Nevertheless, hardly a day goes by that a machinist doesn't make a few calculations of some sort.

With the vast majority of shop math being simple addition and subtraction, many machinists can get by with few math skills. Sooner or later, as a machinist you'll be faced with a problem that elementary math won't solve. If you are able to do trigonometry; find the circumference of a circle and use Pythagorus's theorem then you'll be able to solve most shop math problems.

Like many skills with learning curves, practice makes perfect. Math is no exception. In this chapter, I'd like to present what I think are some interesting and relevant math problems for readers to practice on. Some of these problems are easily solved using a CAD system. Is that cheating? I suppose not. But if you enjoy a challenge then try working them long hand to test and improve your math and reasoning skills.

These are not easy problems for many people so don't get discouraged if you can't get them. Maybe let your co-workers have a stab at them. At the very least you may end up learning something. The answers to these problems are shown in Appendix 2.

1.	How much material must be ground off each wear plate in the diagram below so the cavity blocks can sit flush and centered in the mold base?
2.	In...