Posted on 04/12/2011 1:32:09 PM PDT by grundle
Texas Instruments TI-85 says:
48÷2(9+3) = 2
But Texas Instruments TI-86 says:
48÷2(9+3) = 288
501 :p
Who'dathunkit? LOL Way to go!
Make that 2
I get 1/16. I buy the idea that “2x” means “(2*x)”
I don’t buy that “2(9+3)” means “(2*(9 + 3))”
2ers are assuming that the “/” makes some sort of impenetrable boundary and that it is “2” and only “2” that is being distributed.
I think “48/2” is being distributed across (9 + 3).
(48/2)* 9 + (48/2) * 3
216 + 72
288
Question 1:
Sister Mary Catherine has 48 students in her math class, seated two to a desk. To each desk she distributes a cup containing nine orange jelly beans and 3 red jelly beans. Shared out equally, regardless of flavour, how many pieces of candy does each student receive?
Question 2:
Sister Mary Catherine has 48 students in her math class. To each student she distributes two cups, each containing nine orange jelly beans and 3 red jelly beans. How many pieces of candy has Sister Mary Catherine distributed?
Please show your work....
Ah, but read my next post. That very same sight, when replacing the / with a ÷ (as in the original equation), gives 2 as the answer. So, the / and ÷ are treated differently. Try it at that link.
The calculation is as follows
48/2*(9+3)
Proper order of operations as I understand them are you do the work in the parenthesis then you do the multiplication and division from left to right, then finally any addition or subtraction.
Following this you get the following:
48/2*(12)
24*12
288
If you were to do the multiplication first, you wind up with the answer of 2
48/2*(9+3)
48/2*(12)
48/24
2
The second answer is wrong based on the order of operation rules because it performed the multiplication prior to the division.
Now, there is a caviat, because if the calculator represented the problem as
48
—
2*(9+12)
Then 2 is the proper answer for this, I suspect the mode the cacluator that gave you the answer viewed the problem in this manner or had its input mode set to this. My guess is that the input mode for the calculators are different and one is viewing it as linear as listed at the top, and the other is viewing it as a fraction as listed just above.
But if the problem is written as left to right:
48 divided by 2 times (9+12) the answer is 288.
If it is written as 48 over 2 times (+12) the answer is 2
should read (9+3) where you see (9+12) and (+12) in the last few sentences.
Like I said, some mathematicians (at least one reference found on the internet) insist that a “juxtaposed” multiplication takes precedence over regular multiplication and division. (That there are implied parentheses around the quantity.)
I don’t subscribe to that theory and neither does any software I have ever used. TI did, but corrected their calculators to use standard rules.
Do you agree that
ab(c + d) = abc + abd ?
a=48
b=0.5 i.e (1/2) i.e. divided by 2
c=9
d=3
Exactly correct.
48/2(9+3)=
48/2(12)=
48/(24)= 2
See a Packer fan and a Seahawk Fan agree.
Do this:
Go get a 7th or 8th grader who can do multiplication in their head. (Someone who can multiply or divide 48 by some number in their head)
Read the second line of your math problem out loud.
Hopefully, you’ll say:
“Forty-Eight divided by two times twelve”
Now as you say that out loud, will this middle-schooler have any reason to do the “two times twelve” part first?
we all know tha real answer is 42
It took 517 posts to get there.
Ah yes, sometimes FR does get mean even over the trivial. I'm 61, and find that the young ones don't know anything at all about statesmanship or just ordinary manners.
I hate numerical work on computers since floating point is somewhat ill-behaved. The proper thing to do is to demand clarification of intent from the person originating the problem.
It would appear that there are two teams of firmware authors at TI; and, two understandings of parsing alegebra ... just like at FR. If they think the TI calculators are goofy, they should compare some of the Casios. HP probably makes the only decent calculator these days. I have noticed that much nicer calculators are available in Europe. That probably means we acheived third world status a few years ago.
Take care of yourself as well.
42
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