An annoyance with spreadsheets that deterred me from ever using them in teaching is that they've perpetuated a arithmetic order-of-precedence bug. ("Bug" in the sense that it contradicts long-standing mathematical convention.) If you type
-3^2
in a cell and press ENTER, the spreadsheet tell you it's "9". It should be "-9"; in math, exponentiation has precedence over unary minus, so you square 3, then negate the result. For instance, if you tell students to graph "y = -x^2", they should draw a parabola opening
downward.
I don't have a recent copy of Excel to check this in, but this was the case in the '97 version. I just tried it in the current LibreOffice calc, and it returns "9". My guess is that one of the early spreadsheets messed up the order of precedence, and everybody after copied it for compatibility.
On the other hand, I just tried maxima and python and they both give "-9".
I wonder if this particular problem afflicts people who copy formulas from (say) math books into spreadsheets.
I don't have a recent copy of Excel to check this in, but this was the case in the '97 version. I just tried it in the current LibreOffice calc, and it returns "9". My guess is that one of the early spreadsheets messed up the order of precedence, and everybody after copied it for compatibility.
On the other hand, I just tried maxima and python and they both give "-9".
I wonder if this particular problem afflicts people who copy formulas from (say) math books into spreadsheets.