a quite freakish phenomenon on my calculator

[sunbull]

when I input the following:

12=N
5=I/Y
-100=PMT
CPT PV

then, the result on the screen is actually: 329.4877

In fact, simply 12 times 100 is 1,200

why the result is only more than 300

is my calculator is ruined??

 

[Super I]

Not sure which calculator you are using... did you clear all registers? Is it possible you had a value in there for FV that you didn't clear out?

 

[japheth1]

Sunbull,
It depends on which Calculator you are using. And also make sure you clear out any data from previous work. For HP 12c Platinum, press f, CLEAR FIN, REG.