Calculator help reset ???

I have a casio fx-83 MS so this ones probably almost the same as yours. On the case of the calculator, their should be a quick reference to some calculations. Last time this happened to me, I 'm pretty sure I looked where it said 'mode intialization' and you follow the steps (on mine you type shift clr 2= ). If that is wrong, I'm sure I found out how to fix the problem looking at the quick refrence, so just look around it to see if there is a solution. Look at the data edit on the quick reference as well, as I may have used that.