I'm confused about significant digits in multi-step problems. If I have something like (7.004 +0.2230)/(15.1-0.033+12.07) do I first do the addition and round to 4 sig figs and then do the denominator and round to 2 sig figs and finally divide? Or do I just work everything out and wait till the very end to round? Please help!

Question

drwls · Answer

Do the additions in the numerator and denominator separately, and round the results to the largest significant decimal place in the sum. The numerator would be 7.227 and the denominator would be 27.1.
Then do the division and keep three significant digits, which is determined by the accuracy of the denominator.

I get 0.267, but I'm sloppy at math. See what you get.

Katie · Answer

Thanks a lot. I think it's great what you teachers do on this site. Very generous of you all to help us out.

drwls · Answer

Thank you for your kind words. We can't help everyone, but we try. It's fun to help students understand how to do the problems themselves. Teachers and textbooks are often unclear.