Math PAck 83+

Requires Ti-83+ series calculator, although, there isn't any particular reason why It shouldnt run on any z80 TI calc.
Simply send MATHPACK.8xp to your calc and run.

Complete the Square
This utility will find the roots of ANY quadratic function and display the steps used to do so.

Function Finder
Enter any equation and any value of X and it will solve it.

Cylinder Volume
This finds the volume of a cylinder, given radius, and height.

Sierpinski Area
This finds the volume left/removed at stage N of Sierpinski's triangle.

Decimal2Binary
Converts and integer -4095 through 4095 to binary, displays it, and stores it to Str1