significant numbers?? 1. The problem statement, all variables and given/known data In my textbook significant numbers are numbers that we are certain of in any unit. There are lots of rules about what are significant numbers and what isn't, basically if you have lots of 0's in a number those aren't significant. And if you have a measurement that is approximated that is not significant either. 2. Relevant equations The course is making me drop all non-significant numbers in coming up with solutions. However I am discovering by using detailed measurements with no approximate figures that my solutions are WRONG. For instance using a micrometer I can measure down to thousandths of an inch, as opposed to a ruler. It seems these rules are just assuming all measurements are approximations and a few numbers should always be dropped!! 3. The attempt at a solution I think this may be an outdated thesis from my textbook that is now 20 years old, have any of you studied significant numbers? I hope this isn't standard practice in computing solutions!!