Exact numbers in the final answers

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Dahriel Aron 3A
Posts: 60
Joined: Fri Sep 25, 2015 3:00 am

Exact numbers in the final answers

Postby Dahriel Aron 3A » Thu Oct 01, 2015 11:29 am

Hey guys,
While I did the homework over the summer I noticed that a lot of times I would come up with an answer of say 40.07, and the answer in the solutions manual would say something like 40.13. This probably has to do with discrepancies in the amount of sig figs used throughout all of the calculations made throughout the problem. I was wondering if anyone knew whether or not a discrepancy like this will be marked as wrong for the final answer of a quiz.
Thank you!

Prina Patel 1H
Posts: 62
Joined: Fri Sep 25, 2015 3:00 am

Re: Exact numbers in the final answers

Postby Prina Patel 1H » Thu Oct 01, 2015 1:52 pm

No, I should think not. I'm pretty sure we round up whatever answer we get. So if you got 40.07 it would be 40.1 which would be the same as the answer 40.13 if you didn't include the last number 3. I'm not sure but I think this is what we would do.

Sophia Galluccio
Posts: 20
Joined: Fri Sep 25, 2015 3:00 am

Re: Exact numbers in the final answers

Postby Sophia Galluccio » Thu Oct 01, 2015 2:26 pm

But do we round after every single calculation, for example if its a multistep problem, or do we only round our final answer? Doing one while the other is required is how I usually end up having a slightly off final answer.

Heerali Patel 3A
Posts: 26
Joined: Fri Sep 25, 2015 3:00 am

Re: Exact numbers in the final answers

Postby Heerali Patel 3A » Thu Oct 01, 2015 3:46 pm

Usually, with multi-step problems, you only round for the final answer to avoid the slight differences that occur in the answers if you were to round with every calculation. This also helps with getting a greater accuracy regarding theoretical yields and actual yields.

Megna Patel 1I
Posts: 24
Joined: Fri Sep 25, 2015 3:00 am

Re: Exact numbers in the final answers

Postby Megna Patel 1I » Fri Oct 02, 2015 12:42 am

Rounding errors can accumulate quickly if you round off at each intermediate step, so it is best to simply use the stored values in your calculator in each step. Then apply significant figures when you reach the final answer.


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