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On question E.2. in the textbook, I converted 90 years into 2,838,240,000 seconds. I continued to use this long & precise number in my calculations, meaning I never used sig figs throughout the various steps of the problem. I only used sig figs for my final answer. Are we supposed to use sig figs for each and every step of our calculations, or are we supposed to wait until we get to our final answer before we use sig figs?
My TA said to treat it as if you did all of the intermediate calculations in one step. In other words, you only need to use sig figs in your final answer. I normally just use the numbers stored in my calculator throughout the problem and then write my answer with the correct number of sig figs.
Yes, I believe the standard for most chemistry problems is to round of your final answer using the lowest number of sig figs presented through the original problem. For example, if you original problem gave you measurements such as 1.35, 1.445, and 0.0001, you would round off your final answer to only 1 sig fig since 0.0001 has the least number of sig figs and only has 1 sig fig.
Whenever you are doing a multi-step problem, it is always good to round at the very end. If you round after each step, your answer may come out to be very different and inaccurate. Try your best to keep all of your answers in your calculator so you can go back and use the exact answers in all subsequent steps. But when I write the calculations down, I typically just write a rounded number while using the exact number in my calculations. Then, when you finally reach the end, round to however many significant figures you have been limited to while doing the calculations.
If you're doing a multi-step calculation with various operations and have to add/subtract numbers in one of the steps, the number of sig figs could change to be less than the least number of sight figs given in the problem. Would we use that number of sig figs for our final answer?
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