BA II Plus There are a few usual suspects 1 BGN mode if there s a tiny BGN in the top line of your calc screen your calc is assuming that every payment happens at the beginning of every period immediate annuity or annuity due instead of the default assumption that it s happening at the end of every period ordinary annuity To change this setting push 2nd BGN PMT key then 2nd SET Enter key in the top row then it will change and toggle back and forth between BGN and END mode every time you push SET Note the screen prompts in the top line as you work through the re set They re reminders to help you get the job done 2 P Y and C Y should be set to 1 Anything else will mess up your results Push 2nd P Y I Y key then you ll see P Y some number If it s not 1 then enter 1 and push the Enter key top row not the equal sign key Then push the down arrow and check C Y Set it to 1 the same way P Y means payments per year and C Y means Compounding per year In my opinion trying to learn how to use these and to reset them every time you do a different problem is much more trouble than it s worth so I recommend that you set them to 1 and ignore them 3 Could be something left over from a prior calculation in the FV cell Suggest you enter 0 in any cell that you re not using for your particular calculation That saves you having to clear all the cells with the CLR TVM function 2nd FV Enter 0 in the unused cell and you still have all your previous entries in the other cells so you can use them to do scenarios and range tests and the like eg What if your rate changes from 5 to 6 Just change i y from 5 to 6 and compute again 4 You may have entered the interest rate as a decimal Enter 10 5 as 10 5 then i y not 105 5 You can use the RCL key to check what s entered in each of the memory cells Push RCL and then the memory cell you re interested in checking Have to push the RCL key each time for each cell since if you push RCL and then your first memory cell key to check it then push another memory cell key you have just entered the result from the first memory cell into the second memory cell Probably don t want that 6 Make sure you enter the variables in the correct order Tell the calculator the number then tell it where to put it Not the other way around Number first then memory cell That should give you some diagnostics to try