How to exchange the answer in Casio to a previous one?

Hi I have a Casio fx-991ES Plus calculator and what I want to do is to exchange the value stored in answer to a previous one. Example: I did a calcula

Hi I have a Casio fx-991ES Plus calculator and what I want to do is to exchange the value stored in answer to a previous one. Example: I did a calculation and after I hit the equation mark it showed me an answer. After that I did some more calculations and the calculator stored my recent value in Answer memory. Now I want to go to a previous calculation and store it in memory. If I hit the equation mark again it would do some other calculation what is it?) rather than store the previous calculation I browsed to in the Answer memory. So how can I store a calculation made before a new one in the Answer memory (the quickest one) or if I can't how to store it in a different memory?
Thanks

or:Hi I have a Casio fx-991ES Plus calculator and what I want to do is to exchange the value stored in answer to a previous one. Example: I did a calculation and after I hit the equation mark it showed me an answer. After that I did some more calculations and the calculator stored my recent value in Answer memory. Now I want to go to a previous calculation and store it in memory. If I hit the equation mark again it would do some other calculation what is it?) rather than store the previous calculation I browsed to in the Answer memory. So how can I store a calculation made before a new one in the Answer memory (the quickest one) or if I can't how to store it in a different memory?Thanks

Tags: