Rounding General Chemistry I and II Lab Manual Dakota State University page 232 of 232 Rounding In the significant figures section, I intentionally left out how to round numbers. The rules for rounding are usually a little more involved than most people realize (not much, just a little). Remember that the purpose of rounding is to try to minimize errors in the final results. If we always round down, we know our answer will always be too low; if we always round up, the answer will always be too high. Through proper rounding techniques, we will get a mix of answers that are either too low or too high, and the errors have at least a fighting chance of canceling each other out so our final answer is close to the actual answer. (1) Numbers greater than 5 always round up. Thus, to 4 significant figures, 22.347 becomes 22.35. Keep in mind that any number greater than five will round up; thus 654.235000000004 rounds up to 654.24 to 5 significant figures, because 0.005000000004 is greater than 0.005, even though it is not by much. (2) Numbers less than 5 always round down.
This is the end of the preview.
access the rest of the document.