Idealy, this text wouldn't be here. The fun button will hide it. I just put it here so you can get an idea of how it works.
Press pre to use previous equation again. This can also be done by hitting the equal after doing a operation
twice, I.E. 2+3, then +3, then equal will keep adding 3.
Ans key will act as a storage of the previous answer.
Set will set the memory storage to the current number selected (works better after hitting equal).
Mem will be 0 by default, can be set by Set key.
The "Fun" key changes the background color.