I would expect the second answer to be a "bug". Computing left to right, 10 divided by 5 is 2, which multiplied by 2 is 4. Your question makes me wish I had the TI-82 manual at home. It might be a matter of the calculator's "guts" somehow attributing the non-symbolic multiplication a higher priority, as if the 5 times 2 were grouped together. This might also be a clue as to how some of my best and brightest students obtained erroneous results while working on problems which I knew should be simple to them.
Jerry Brodkey wrote:
> One of my former students who is now starting to teach asked me the > following question for which I don't have a good answer; > > On the TI-82: 10/5*2 equals 4 > > but 10/5(2) equals 1. > > The order of operations rules that I've been using for twenty years would > agree with the answer equal to one. Multiplication and division are > "equal" in power and you work from left to right. The parentheses in this > case don't change the order of operations. > > Have I missed something? Thought I'd throw this out to the list serve > for any thoughts. > > Thanks , > Jerry Brodkey > Menlo-Atherton High School > Atherton, Ca