
1. Re: Do the following math in your head: 17.5 minus 0.5 plus 3 divided by 4 = ? ; now do the same arithmetic on any stand alone hand held calculator. Same answer right? Now do the same on the iPhone/iPad calculator app. Why the different answer?
WiseJD Nov 12, 2012 4:39 PM in response to Geff SI get 5 on my iPhone 5.
Keys...
17.5 "" .5 "=" 17 "+" 3 "=" 20 "Div" 4 "=" 5

2. Re: Do the following math in your head: 17.5 minus 0.5 plus 3 divided by 4 = ? ; now do the same arithmetic on any stand alone hand held calculator. Same answer right? Now do the same on the iPhone/iPad calculator app. Why the different answer?
Geff S Nov 12, 2012 4:41 PM in response to WiseJDI get 17.75 on my iPhone 4.

3. Re: Do the following math in your head: 17.5 minus 0.5 plus 3 divided by 4 = ? ; now do the same arithmetic on any stand alone hand held calculator. Same answer right? Now do the same on the iPhone/iPad calculator app. Why the different answer?
Geff S Nov 12, 2012 4:45 PM in response to Geff SIF I punch the "=" between each you do get 5 punch if you don't hit "=" between each you get 17.75. I don't have to keep hitting "=" on a regular calculator.

4. Re: Do the following math in your head: 17.5 minus 0.5 plus 3 divided by 4 = ? ; now do the same arithmetic on any stand alone hand held calculator. Same answer right? Now do the same on the iPhone/iPad calculator app. Why the different answer?
steve359 Nov 12, 2012 4:47 PM in response to Geff SCould be AOS ... Algebraic Operating System operator priority.
3/4 is performed first, yielding .75
17  0.5 + 0.75 = 17.75
Different applications prioritize multiply/divide over plus/minus. Try putting () around the first 3 operations in iPhone/iPad to ensure thay are done first.

5. Re: Do the following math in your head: 17.5 minus 0.5 plus 3 divided by 4 = ? ; now do the same arithmetic on any stand alone hand held calculator. Same answer right? Now do the same on the iPhone/iPad calculator app. Why the different answer?
WiseJD Nov 12, 2012 4:48 PM in response to Geff SWhat you did was...
17.5 "" .5 "+" 3 "Div" 4 "=" 17.5
Different key strokes made the outcome change.

6. Re: Do the following math in your head: 17.5 minus 0.5 plus 3 divided by 4 = ? ; now do the same arithmetic on any stand alone hand held calculator. Same answer right? Now do the same on the iPhone/iPad calculator app. Why the different answer?
Lawrence Finch Nov 12, 2012 4:56 PM in response to Geff SGeff S wrote:
IF I punch the "=" between each you do get 5 punch if you don't hit "=" between each you get 17.75. I don't have to keep hitting "=" on a regular calculator.
That's because a "regular" calculator is too stupid to understand precedence of operations. As you learned (I hope) in 7th grade math (or possibly earlier if you went to a good school) in a string of operations multiplication and division are evaluated first, then addition and subtraction. So in your example 3 divided by 4 is evaluated first, then the result (.75) is added to 17.5  .5. Giving the correct answer of 17.75.
BTW, my "regular" calculator also give the correct answer.

7. Re: Do the following math in your head: 17.5 minus 0.5 plus 3 divided by 4 = ? ; now do the same arithmetic on any stand alone hand held calculator. Same answer right? Now do the same on the iPhone/iPad calculator app. Why the different answer?
steve359 Nov 12, 2012 4:59 PM in response to Lawrence FinchI prefer RPN calculators. Precedence is irrelevant.
But to each his/her own.

8. Re: Do the following math in your head: 17.5 minus 0.5 plus 3 divided by 4 = ? ; now do the same arithmetic on any stand alone hand held calculator. Same answer right? Now do the same on the iPhone/iPad calculator app. Why the different answer?
Lawrence Finch Nov 12, 2012 5:01 PM in response to steve359Yes, my "regular" calculator is an HP12C, which does RPN. I also have a HP12C emulator on my iPhone.

9. Re: Do the following math in your head: 17.5 minus 0.5 plus 3 divided by 4 = ? ; now do the same arithmetic on any stand alone hand held calculator. Same answer right? Now do the same on the iPhone/iPad calculator app. Why the different answer?
WiseJD Nov 12, 2012 5:06 PM in response to WiseJDMy answer in the above actually was 17.75 not 17.5

10. Re: Do the following math in your head: 17.5 minus 0.5 plus 3 divided by 4 = ? ; now do the same arithmetic on any stand alone hand held calculator. Same answer right? Now do the same on the iPhone/iPad calculator app. Why the different answer?
steve359 Nov 12, 2012 5:07 PM in response to Lawrence FinchMy "daily sacrificecapable" HP is a 28S ... infinite stack instead of just X/Y/Z/T. But battery door will eventually pop off for good and many many function never used.
I bought a 15C that HP rereleased that uses 2 CR2032 instead of the original 3 baby batteries.

11. Re: Do the following math in your head: 17.5 minus 0.5 plus 3 divided by 4 = ? ; now do the same arithmetic on any stand alone hand held calculator. Same answer right? Now do the same on the iPhone/iPad calculator app. Why the different answer?
steve359 Nov 12, 2012 5:20 PM in response to Geff SI hope this additonal information is relevant ...
If you plan to write in any programming language (Java, Perl, C, C++) you need to familiarize yourself with the "operator precedence" chart. Programmed states get very tricky mixing ">" (accessing structure member through a pointer) "++" preincrement such as "++strptr>strmember" and the precedence chart is crititcal to programmers.