Just confirming that it’s not possible to calculate anything other than PV and FV on the HP12c? If I put in PV, FV and n for example, I’m unable to calculate the interest rate that would grow PV to FV over n. So basically, need to learn equation 14 of reading 5 - although admittedly it’s pretty easy to derive. Or am I doing something wrong?

Given _ **any** four_ of *n*, *i*, PV, PMT, and FV, you can calculate the fifth.

hmm I get error 5 if I try PV=100 FV=111 n=1 PMT=0 and then press i.

similarly get error 5 if I try to do example 17 PV=10503 FV=14146.4 n=4 PMT=0.

In the manual on page 182 or 179 of the pdf

http://h10032.www1.hp.com/ctg/Manual/bpia5309.pdf

it talks about the conditions for these errors and it states that error 5 will occur if PMT=0 which it must be to carry out such a calculation.

Ah never mind I figured out what I was doing wrong. I was putting in +ve values for both PV and FV… have had this problem before.

Yup.

They’re cash flow buttons.