Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Re: Calculator question
Replies: 0

 LMarks/DVanLeeuwen Posts: 2 Registered: 12/6/04
Re: Calculator question
Posted: Jul 22, 1998 6:45 PM

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