Good o' RPN calculators! I still have my HP35 from 1972 and use an HP15C (I think that's the number) daily. I still agree with the old T shirts that [ENTER] > = . I teach electronics at night at the local community college. My students all have very fancy calculators that use algebraic notation. And they consistently get the wrong answer. They're always leaving out parenthesis and having the calculator solve a problem other than the one they want. RPN solves this by having you work the problem the way you would by hand: from the inside out. Also, you see all intermediate results so you can catch errors if you have a feel for the numbers. On rounding, here's an example: 1.5+2.5 = 4.0 without rounding With rounding using "round to even" 2 + 2 = 4 With "rounding up" 2 + 3 = 5 Round to even tends to minimize error. Harold On Thu, 31 May 2001 07:31:01 -0500 michael brown writes: > I'm pretty old myself (39), but I have seen calculators that have > something > called 5/4 rounding. Being uneducated (no degree) I'm not sure what > that is > about. Remember the good ole RPN calculators? If you could > understand how > to use one of those, you were well on your way to being a FORTH > programmer. > > Michael Brown > Instant Net Solutions > www.KillerPCs.net > > > > > > Hi Michael, yep, darn right, half the people in > > the world (including me!) have been rounding wrongly > > their entire lives. Very scary. There is and can only > > be one correct way of rounding decimal numbers... > > > > Here is an example, assuming rounding to 3 decimal > > places, that is 1000 combinations, from 000 to 999. > > > > 000 to 499 (first half), 500 to 999 (second half). > > There are the first 500 combinations in the first > > half, and the second 500 combination in the second > > half. > > > > All my life I have been rounding at 555, under the > > false impression that 5 is "half way" in decimal > > terms... Wow. > > > > I asked my 26 yr old science-degreed girlfriend how > > to round and she looked at me like I was stupid. > > "5 or more, round up". She was taught correctly. > > > > Now I'm wondering if it is mainly us old-timers > > from the dawn of pocket calculators age that were > > taught wrong?? Any thoughts, older people?? > > :o) > > -Roman > > > > > > michael brown wrote: > > > > > > > roman, > > > > > > > > i was taught to round up if it's >= 1/2. little different > than you > > > system - little easier > > > > > > > > > 3.12471 = 3.125 > > > > > 3.12441 = 3.124 > > > > > 3.1245551 = 3.124 > > > > > 3.1245556 = 3.125 > > > > > > > > 3.1247 = 3.125 7 >= 5 round up > > > > 3.1244 = 3.124 4 < 5 truncate > > > > 3.1245 = 3.125 5 >= 5 round up > > > > 3.1245 = 3.125 5 >= 5 round up > > > > > > > > ie: i only check the 4th digit. if it's >= 5 round up. if not > truncate. > > > > > > > > -pete > > > > > > Finally some one got it right! ;-D Way to go Pete. If you > want to > round > > > to N decimal places then look at position N+1. If position > (N+1) >4 > then > > > increment position(N). That's all there is to it. You don't > have to > look > > > at anything else. Hope this helps. TTYL > > > > -- > > http://www.piclist.com hint: To leave the PICList > > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > > > > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! For your FREE software, visit: http://dl.www.juno.com/get/tagj. -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu