Math in general, I apply the main math focus and they are addition, subtraction, division and multiplications. Unless it is part of our job, Physics and Geometry, Trigonometry, Calculus and other math operation will be useful. Sometimes I am thinking that having to know addition, subtraction, division and multiplication are just enough to survive to solve math problems in general. You must know the basic. There are lots of people succeed in life with only the general Math operation are known. Also, unit of measurement and its conversion are a big help too. Learning how to measure and how to convert the road where how many kilometers you will walk or pass through cars, your weight converted to inches or centimeters. I think that is enough.