If you notice there is a small k on the bottom right. The constant. Here is information about it and how to set it. I can be used for "good" not "evil" For example: If you are doing a process over and over like # X 2 + 3. You can store the operations as k, then just put in the number and hit =. If you put in a 9 and hit =. It would show 9 X 2 + 3 = 21. Or maybe just X 2. Old calculators, you could hit the = to keep doing the same thing like X 2, X 2, .... This is what the k does. How do I use the constant K function on the TI-30X IIS/B?: On the TI-30X IIS/B, pressing [2nd] [Division] turns on the constant mode and allows the user to define a constant. K appears in the top of the display when the constant mode is on. The [=] key places the contents of K at the end of the expression in the display. To enter a constant: 1) Press [2nd] [Division]. If a constant is already stored, press [CLEAR] to clear it. 2) Enter a constant (any set of operations, functions, and values). 3) Press [=] to turn on the constant...