The Museum of HP Calculators

HP Forum Archive 19

 Checking my daughter's homeworkMessage #1 Posted by Sancerre (Phoenix) on 12 May 2009, 6:59 p.m. My daughter asked me to go over her homework. Today's lesson covered operations with fractions. After going through the work manually, we took out our calculators to check the work. I do most of my work on my 50G, but chose my 35s since it is so easy to enter/calculate/display fractions. We looked at the following problem: 1/5 + 3 7/8 (that is one fifth plus three and seven eights). Our manual solution was 3 3/40. However, the 35s came out with 3 1/13. Naturally, this wasn't a good thing with my 10 year old daughter watching. So, we did the same calculation on her Smartcalc 300s. The 300s confirmed our manual result. I then entered the calculation as an equation on my 50g, it came back with the same answer as the 300s. So, how come the 35s came back with a different solution? I must be making some stupid mistake (it has been a long day!). Or, is this some display setting with fractions on the 35s? --Tod

 Re: Checking my daughter's homeworkMessage #2 Posted by Sancerre (Phoenix) on 12 May 2009, 7:23 p.m.,in response to message #1 by Sancerre (Phoenix) Sorry, it has been a long day. The answer(s) are 4 3/40 or 4 1/13.

 Re: Checking my daughter's homeworkMessage #3 Posted by Paul Dale on 12 May 2009, 7:30 p.m.,in response to message #1 by Sancerre (Phoenix) You've probably (accidentally) set a small maximum denominator via the /c command. Try 100 /c and see what result it gives. 0 /c should reset to maximum. Remember the 35s doesn't do real fraction like the 48 series. - Pauli Edited: 12 May 2009, 7:32 p.m.

 Re: Checking my daughter's homeworkMessage #4 Posted by Sancerre (Phoenix) on 12 May 2009, 7:50 p.m.,in response to message #3 by Paul Dale Yes, that was the answer. Thanks for the fast response. --Tod

 Re: Checking my daughter's homeworkMessage #5 Posted by Thomas Radtke on 13 May 2009, 7:06 a.m.,in response to message #4 by Sancerre (Phoenix) There are two (easy to overlook) indicators to the right, showing up when the true result is smaller or larger than the fraction shown. Edited: 13 May 2009, 7:06 a.m.

 Re: Checking my daughter's homeworkMessage #6 Posted by Bernard Rochlin on 12 May 2009, 7:31 p.m.,in response to message #1 by Sancerre (Phoenix) Your answer should be 4 3/40 On the HP50g one enters 5 1/x then 3 7 8 / + PROPFRAC PROPFRAC Edited: 14 May 2009, 7:54 p.m.

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