The Museum of HP Calculators

HP Forum Archive 19

 Why engineers need both scientific and business calculatorsMessage #1 Posted by Martin Pinckney on 18 Aug 2010, 11:05 p.m. In addition to the obvious need for TVM and date calculations, I find the % functions on scientific calculators to be woefully lacking for the kind of % calculations that I do on a regular basis. Even the 27s (my overall favorite), which has excellent TVM and date math, only has the typical scientific implementation of % math. Of course I could easily write a Solver routine, but that takes precious memory. This is one reason why I always keep a 17b handy. Following the recent thread on the 30b, I was gratified to see it also has the full implementation of % math, what the 17 series calls "Business" functions (%Change, %MU-cost, %MU-price, %Total). With the added bonus of the scientific functions, I can see why it has developed a big following.

 Re: Why engineers need both scientific and business calculatorsMessage #2 Posted by Angel Martin on 19 Aug 2010, 2:05 a.m.,in response to message #1 by Martin Pinckney I always suspected me as not a good engineer, I guess now I know why :) Well, I did my part to redeem myself - the SandMath module includes a %Total function, but I confess not having any inkling about the "other" percentages you mention. Many times I found the issue with financial terms was on their insisstence to name and label every possible ratio, inverse ratio, and combination of ratios. The real problem for me wasn't to calculate what you needed to find out, but to "map out" the available ratios names to the problem in question. Just as I said, typical of a bad engineer no doubt :) Cheers, "AM

 Re: Why engineers need both scientific and business calculatorsMessage #3 Posted by Paul Dale on 19 Aug 2010, 3:24 a.m.,in response to message #1 by Martin Pinckney %Change is on many scientific calculators already. %MU-cost corresponds to "% +" which isn't onerous. %Total is "SWAP / 100 *", again not too difficult. I doubt that a decent engineer would have trouble with any of these :-) I'm not sure what %MU-price is. - Pauli

 Re: Why engineers need both scientific and business calculatorsMessage #4 Posted by Martin Pinckney on 19 Aug 2010, 9:38 a.m.,in response to message #3 by Paul Dale Quote: I doubt that a decent engineer would have trouble with any of these :-) Wow, and I always thought I was a decent engineer. Quote: Sheesh. I think I'd prefer to just do those operations myself, based on what I wanted to do at any given time. The minuscule amount of time I'd save by having them be built in functions would have to be more than offset by the difficulty of memorizing what percentage operation does what. Seriously, though you could say the same about many built-in functions. But isn't that the value of having a calculator with many built-in functions, to save time? Why don't we all just go back to using the HP 35, and forget about all the added utility since.

 Re: Why engineers need both scientific and business calculatorsMessage #5 Posted by Norman Dziedzic on 19 Aug 2010, 1:01 p.m.,in response to message #3 by Paul Dale > I'm not sure what %MU-price is. This is used when you want to make a specific margin on selling an item. For instance, if it costs you \$20 for something and you want to make a 15% margin, you don't sell it for 20*1.15=\$23.00. You have to sell it for 20/(1-.15)=\$23.529. The %MU-Price does this. All our commissioned sales people use this type of calculation all the time. Many can do it in their heads but none of them use HP calculators :-(

 Re: Why engineers need both scientific and business calculatorsMessage #6 Posted by Paul Dale on 20 Aug 2010, 7:47 p.m.,in response to message #5 by Norman Dziedzic Thanks for this. I know of this just not by the name given. Something to add to the firmware when I eventually get back to it. - Pauli

 Re: Why engineers need both scientific and business calculatorsMessage #7 Posted by Walter B on 19 Aug 2010, 4:40 a.m.,in response to message #1 by Martin Pinckney Do you think of something like this?

 Re: Why engineers need both scientific and business calculatorsMessage #8 Posted by Paul Dale on 19 Aug 2010, 4:48 a.m.,in response to message #7 by Walter B I spy the percent functions from the stalled 20b/30b scientific firmware :-) - Pauli

 Re: Why engineers need both scientific and business calculatorsMessage #9 Posted by Walter B on 19 Aug 2010, 7:06 a.m.,in response to message #8 by Paul Dale Pauli, you hit the nail on the head. I didn't want to invent the wheel twice. BTW, there are some minor updates in the project docs ...

 Re: Why engineers need both scientific and business calculatorsMessage #10 Posted by Crawl on 19 Aug 2010, 8:46 a.m.,in response to message #7 by Walter B Sheesh. I think I'd prefer to just do those operations myself, based on what I wanted to do at any given time. The minuscule amount of time I'd save by having them be built in functions would have to be more than offset by the difficulty of memorizing what percentage operation does what.

 Re: Why engineers need both scientific and business calculatorsMessage #11 Posted by Walter B on 19 Aug 2010, 9:26 a.m.,in response to message #10 by Crawl :) So do I. But typical users of business calculators are ... different ;)

 Re: Why engineers need both scientific and business calculatorsMessage #12 Posted by Ken Shaw on 19 Aug 2010, 9:58 a.m.,in response to message #10 by Crawl Absolutely. The %-related keys are the biggest waste of real estate on all the keyboards. My main calculator is the 17BII and I have no use for the % key.

 Re: Why engineers need both scientific and business calculatorsMessage #13 Posted by Martin Pinckney on 19 Aug 2010, 10:28 a.m.,in response to message #12 by Ken Shaw Quote: My main calculator is the 17BII and I have no use for the % key. Just to be clear, I wasn't talking about the % key on the 17 series, but the % functions in the [BUS] softkey menu. I for one find them to be very useful. Am I the only engineer (or non-business type) on here that does?

 Re: Why engineers need both scientific and business calculatorsMessage #14 Posted by Bruce Bergman on 19 Aug 2010, 10:40 a.m.,in response to message #13 by Martin Pinckney You're not the only one -- I like 'em too. ;-) Thanks, Bruce

 Re: Why engineers need both scientific and business calculatorsMessage #15 Posted by Martin Pinckney on 19 Aug 2010, 5:21 p.m.,in response to message #14 by Bruce Bergman Thanks, Bruce.

 Re: Why engineers need both scientific and business calculatorsMessage #16 Posted by Palmer O. Hanson, Jr. on 20 Aug 2010, 4:07 p.m.,in response to message #1 by Martin Pinckney If you need both a scientific and business calculator then why not get a 19BII?

 Re: Why engineers need both scientific and business calculatorsMessage #17 Posted by Jeff Kearns on 21 Aug 2010, 7:09 p.m.,in response to message #16 by Palmer O. Hanson, Jr. Hear, hear! I bought one in mint condition a few months ago for \$40CAD and enjoy using it. I have stored a number of useful equations in it, such as solving for Canadian mortgages and some machine design problems in pressure vessel design. BUT, for pocketability, I often bring the 12C to meetings. Jeff

 Re: Why engineers need both scientific and business calculatorsMessage #18 Posted by Martin Pinckney on 21 Aug 2010, 8:45 p.m.,in response to message #16 by Palmer O. Hanson, Jr. Clamshell design is why not. 27s comes closest, except maybe the new 30b might fill the bill. That was my original point. Edited: 21 Aug 2010, 8:46 p.m.

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