The Museum of HP Calculators

HP Forum Archive 13

 "n" function in HP 12CMessage #1 Posted by Luc on 31 July 2003, 11:51 p.m. Hi all, Any one know why the HP 12C calculator rounds the calculated value of "n" up to the next higher integer? Example: for a financial problem, when we solve to get the Number of Payments or Compounding Periods "n", the correct answer is n=3.1 years (just for example), but the HP 12c will answer n=4 years. Oh, It's surprised. And, this situation also occur on the Financial Consultant Casio FC-200. Luc

 Re: "n" function in HP 12CMessage #2 Posted by Gene on 1 Aug 2003, 8:39 a.m.,in response to message #1 by Luc Well, in truth, you can't make 3.1 payments in real life. The designers decided that they would report a value for n that would make sure the PV or FV had actually been reached. In your example, after 3 payments, you haven't quite had enough put in. At 4 payments, you are beyond it. They chose to use 4 rather than 3, and didn't like the "exact" solution for n as noted above. That said, I wish they had decided to just report the real n and let users round up. Users are not stupid, but that's something calculator designers sometimes forget. Cheers!

 Re: "n" function in HP 12CMessage #3 Posted by Luc on 1 Aug 2003, 8:38 p.m.,in response to message #2 by Gene Hi Gene, Are you "Gene Wright" author of some books in which is "Quantitative Analysis For Business - The Time Value of Money and Basic Business Statistics - Using a Business Calculator"book ? I saw on Amazon, but the book is expensive (as for me - Vietnamese) > 40USD. OK, thank you for you answer !!! But in HP 10B, it is not happen that case of "n", HP 10B give a correct answer, it same to answer og TI BAII+. And HP 12C and Casio FC-200 gave an answer of "n" same together with round up to next interger. cheers Luc Edited: 1 Aug 2003, 9:06 p.m.

 Re: "n" function in HP 12CMessage #4 Posted by Gene on 1 Aug 2003, 10:20 p.m.,in response to message #3 by Luc Yep, that's me. Sorry for the high price. I can't do a very big print run and that drives unit cost up. :-( They implemented the solution for n differently in the HP-10B, etc. I dont' know why the HP-12c was made the way it was. The BAII Plus is a great cheap calculator for business students. If they made a good keyboard it would be fantastic. Our university changed the recommended calculator to the TI BAII Plus last year because of the terrible HP-10BII keyboard. Sadly, leaked pics of the new business calculators rumored to be coming appear to show the same keyboard. I hope they worked that part out.

 Re: "n" function in HP 12CMessage #5 Posted by hugh on 4 Aug 2003, 7:30 p.m.,in response to message #1 by Luc also, the 12c has a special meaning for n input as a non-integer. the fractional part is intended for the odd payment. ie that fractional part of loans to cover the intermediate time before it starts proper. only as input tho'.

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