rounding between steps
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rounding between steps
In the achieve homework, there were questions that required you to complete the ICE chart to solve for x before using -log to find the pH of the solution. So when you are calculating for x from the ICE chart, how much do you round by before finding the pH?
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Re: rounding between steps
I usually just keep the x value in my calculator and then plug that number right into -log(x) to find the pH to make sure my answer is as accurate as it can be.
Re: rounding between steps
with problems that involve calculations, I typically do not round until the last step so I would keep the value of x on my calculator and use that to calculate the ph and then rounding to the needed sig figs after.
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Re: rounding between steps
Personally, I try to keep the same number of significant figures as the measurements or values given in the question as I am working through the problem. If one of the given values has a smaller number of sig figs than the other given values, I try to keep my calculations within that lowest sig fig count.
But, I agree that using the values as returned by your calculator is probably more accurate!
But, I agree that using the values as returned by your calculator is probably more accurate!
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Re: rounding between steps
For me, I try to keep a really long amount of numbers as I go through the process and then at the very end round and then fit it into the amount of sig figs that I need. By rounding or truncating early, you risk having more errors within your final answer.
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Re: rounding between steps
Similar to everyone else, I usually use the value on my calculator, and then round when I get my final answer. Keeping more sig figs makes the answer more precise, so it's best to leave it longer until the end. Hope this helps!
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Re: rounding between steps
It's a total pain, but usually its best to only round at the very end to get the most exact answer possible. It definitely makes problems take longer but in my opinion its worth it.
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Re: rounding between steps
Usually, I tend to try and not round or at least over 5 digits after the decimal. I like to do this if there are many steps to the problem. If the problem is more simpler, you can keep it in your calculator and it will be easy to recover after.
Re: rounding between steps
I usually use 5 decimal places and it worked out painlessly for me. If there are more than 5, you'll probably be using exponents.
Re: rounding between steps
Usually, I round to about four or five decimals as I work the problem, and then I round to the number of significant figures for the very last part of a problem. I don't know if this is the best way to do it, but for the achieve hw it works for me and makes it a little easier to keep track of the numbers.
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Re: rounding between steps
I usually do not round until the end of the problem by saving values on my calculator. When I round at the final answer, I match the sigfigs from the problem.
Re: rounding between steps
I would keep as many as possible when doing the -log of a number because when rounding a lot this can easily affect your results and cause them to be wrong. If you need to round, try to keep at least 5 sig figs.
Hope this helps!
Hope this helps!
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Re: rounding between steps
Personally, I do not round my answer throughout the steps I wait until I am completely done. I wait until the final step because I fear if I round each step the answer will be incorrect, and so far rounding at the end has been working for me (regarding achieve).
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Re: rounding between steps
Hi Vicky,
When I encounter there type of problems, I keep everything (like the X value) in my calculator, and plug the whole thing into the equations that I use. I do this until the very last step, and then I round according to the least amount of sig figs in the question. This way, everything is accurate.
For showing work (like notes), I just round it to 5 decimal places but keep all of the decimal places in my calculator.
When I encounter there type of problems, I keep everything (like the X value) in my calculator, and plug the whole thing into the equations that I use. I do this until the very last step, and then I round according to the least amount of sig figs in the question. This way, everything is accurate.
For showing work (like notes), I just round it to 5 decimal places but keep all of the decimal places in my calculator.
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Re: rounding between steps
Hi! Normally when I am using a calculator I do not round anything until the last step, but if I were to round I would use significant figures to determine the numbers.
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Re: rounding between steps
During my TA session and other workshops, it was always recommended to not round until the end. If you have a graphing calculator you can always store the numbers while you work out the problem. Hope this helps!
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Re: rounding between steps
I had the same question, and was told to wait til the end. However, sometimes that gets a little difficult to keep track of and I Have found that if you have 4/5 decimal points throughout, the answer is usually close enough that when you round in the end it works out to be correct. Also, since we have unlimited attempts on achieve, typically if I find myself struggling I will try answer choices that are one decimal above/below, and usually one of those ends up being correct.
Re: rounding between steps
Since it is all on my calculator, I usually do not round until the last step.
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Re: rounding between steps
For simpler problems, I usually do not round until the last step and insert values directly from my calculator. However, with problems with many steps, I think it is safe to keep 5 sig figs from step to step.
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Re: rounding between steps
I try not to round until the very end and just use the values on my calculator along the way to make sure that my answer is as accurate as it can be.
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Re: rounding between steps
As many others have stated before I tend to not round until the very last step and in terms of sig figs I try to keep it equal to the lowest amount of sig figs from other values within the problem.
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Re: rounding between steps
For problems like the ones we see on the homework, I normally save the rounding for the very end. I personally do all of my calculations with the full numbers just to be cautious that no steps are being done wrong because I rounded too soon or something.
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Re: rounding between steps
I think it is best to keep the actual values when doing your calculations and then rounding the final answer to the appropriate amount of sig figs so you get an accurate answer.
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Re: rounding between steps
I try to keep the values in my calculator so that I can just round once at the very end.
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