Depends on the app you are writing. For example - in my daily work I've used math more complicated than computing average/sum of numbers only a few times in 5 years. Once it was geometry on a plane when writing code for pathfinding in a warehouse (great fun :) ), other times it was mostly to calculate amounts of goods based on something (mostly converting units, calculating volumes, etc - basic stuff).

My hobby is wrtiing games, mostly 2d, but I've tried doing 3d too, and there you use math much more often. Mostly 2d/3d geometry, integration for game physic (for most purposes naive Euler integration suffices, and it's really simple, you can invent it without knowing about physics, nor what integral is, but still - it's math). Also requires math - collision checking, ai, space indexing, pathfinding.

When optimizing something, basic statistic is handy, but not required. And sometimes it's nice to be able to come up with Fermi-style estimate of something - like how much cpu time/memory you will need if you make this initial decision or that.