<p dir="ltr">Good question!</p>
<p dir="ltr">I don't have a specific test sequence to offer. I do recall that division is the divergent operation based on binary math, endianess and integer size. I think a search for "errors in decimal division converted to binary" may help find numerical tests.</p>
<p dir="ltr">That said, the more modern calculators may have error correction for those corner cases now.</p>
<p dir="ltr">All of my calculator failures have been display death or battery leaks.</p>
<div class="gmail_quote">On Sep 20, 2015 9:39 AM, "Tom Freeman" <<a href="mailto:tfreeman@intel.digichem.net">tfreeman@intel.digichem.net</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
I ran into a problem a while back, and I'm wondering if anybody has a decent answer.<br>
<br>
Working at the board, I raced the students to get a calculation performed. I shouldn't have bothered. Our respective results diverged about the fourth place, with my little TI-30XA being a minority of one. (Sadly, I didn't think to write the problem down for further investigation.) I switched to a backup graphing calculator, and things went smoothly.<br>
<br>
Question that some googleing hasn't properly answered: How do you test a simple hand calculator to demonstrate proper operation?<br>
<br>
Obviously, the simple response is to dump the suspect calculator. Trash it with extreme predjudice as it were.<br>
<br>
However, since there are individuals on this list who need extended precision in their work, I wonder if they know how to test a hand calculator for correctness.<br>
<br>
Come to think of it - having a faulty calculator or three and a testing procedure might be a good instructional process for students. We do need to trust our equipment, and we need to continuously check it for error.<br>
<br>
In any event, my thanks to the list for the use of their bandwidth.<br>
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