Question

Using the rules for significant figures, what do you get when you subtract 15.54 from 508.9538?
493
493.4
493.41
493.413
493.4138

Answer 1

@PlatoMaster

Answer 2

For addition and subtraction, look at the decimal portion (i.e., to the right of the decimal point) of the numbers only. Here is what to do:

1) Count the number of significant figures in the decimal portion of each number in the problem. (The digits to the left of the decimal place are not used to determine the number of decimal places in the final answer.)

2) Add or subtract in the normal fashion.

3) Round the answer to the least number of places in the decimal portion of any number in the problem.


508.9538-15.54= 493.4138 is the normal difference. However you need to apply sigfig rules. Which had the least sigfigs after the deC*imal? and that is how many your answer should have.

Answer 3

Thanks!!!!