Significant Figures

When working in class, especially with our equipment that isn’t’t worth millions of dollars, we can’t be sure that the measurements we get are completely accurate, we could be of by a thousandth of milligram, and it would affect the final result, that is where significant figures(maybe ) come flying in, and you are able to show that you accounted for the fact that you didn’t have all the information by using the significant figure method.

Rules

  1. Non-Zero Digits are always significant (as in, when counting out how many sig figs there are, every digit will certainly be counted)
  2. Any zeros between two significant #’s should be counted (So if there’s something like 5005, that’s 4 sig figs
  3. Trailing Zero’s Are Significant (After your non-zero digits finish out, and there’s still zero’s afterwards? To the right? Those are significant figures! Say you were writing out measurements and the scale came out with 2.20, that’s 3 sig figs)

Multiplication/Division and Addition/Subtraction

Multiplication/Division

For the entire number, after you’ve solved through the problem, use the least amount of significant figures from what you were originally working with

Addition/Subtraction

Only look at the significant figures after the decimal of the numbers you are working with, and when you find your answer, on the right of your decimal, make sure it’s the amount of sig figs determined beforehand.

Important Things to Remember

Only apply significant figures after you’ve completely solved through the problem, as that will bring you the most accurate results. Also, if say you get an answer of 5000? You need to write that out in scientific notation, either as 510^3, 5.010^3, 5.00*10^3, etc.

Conclusion

And those are our figures that are significant, will help you read some multiple choice answers and might be nice to remember on some tests