Ok I discovered this some time in maths when a student wrote a quadratics solver program (I might upload this as its very useful). Basically you can easily write yourself messeges, sentences, paragraphs, mathematical equations or rules or anything that you might find useful during a test. It is up to you whether or not you use this to cheat.
Ok here we go
Step 1:
Press the PRGM button on your graphics calculator
That will bring up this screen:

Step 2:
Move across to the right to NEW and select the 1st option, Create NEW
Name it whatever you want but obviously nothing suspect.
Step 3:
Now quit and go back to the PRGM menu and go across to EDIT and select the program you just created.
Step 4:
Now its time to write some VERY simple code.
Open up Quotation marks (press ALPHA then the + button down the bottom right of your calculator)
Now you are free to write any messege you wish.
After you are done simply close the Quotaion marks.
Step 5:
Simply click into PRGM menu again only this time all you have to do is select your program and hit enter, then enter again to activate it.
There you have it you can write yourself notes or answers for tests or simply create programs as study guides (I made a vector table which was useful as we had to remember 9 different things).
Step 6:
Ok so incase you don't want to leave any evidence of what you have done you may want to delete the program you have made.
Press 2nd, MEM, 2: Delete, 7: Prgm. This shows a list of all programs with the cursor pointed at the first one. Use the up- or down-arrow keys to place the cursor in front of the one you want to delete, then press ENTER. Repeat for all programs that are to be deleted.
After this your program names may remain there but the information contained within them will be gone, so take caution in naming your programs.
Instead of uploading Quad solver as a file here is the code for it:

When you run this program simple put in a,b,a when it asks you and it will return the value(s) of x.
Im going to sleep now, leave comments, corrections and I will correct any errors tomorrow.
If you like this guide please +rep me it wasn't easy taking all the screen shots and fiddling round with the programs.