Let's be honest, if you are doing serious math, you'll have a graphing calculator to do way more stuff, and the controls are much more like a mini computer (with a backspace key, and being able to delete individual lines of history, or all of the history with menus)
Ive been forced to use it a bit and it has so many weird quirks that are just messed up. Index start at 1. Sometimes u have to assign some function output to a variable before u can pass it as an argument to another function.
I far prefer to use python with numpy matlab and scipy