Integrals
Typically used in calculus when trying to find the area under a curve. Integration can be used to find areas, volumes, central points and many useful things, but is easiest to start with finding the area under the curve of a function like this: What is the area under y = f(x)? Also, due to it being affiliated with calculus, it may make you look smarter than you actually are.
John: Hey did you figure out how to solve question 186b? Bob: It was easy! You simply had to use integrals!
By OhlookImoaned