# problems- significant figures

i have to do a chemistry problem and i have to express the results to the correct number of significant figures.

problem: 8.27 (4.987 - 4.962)

2nd step: (8.27) (.025)

(the rules for multiplication and division are the number of significant figures in the result is the same as the number in the least precise measurement used in the calculation. )

.025 has only 2 significant figures but it's not in the original problem. my question is do i count that as a limiting number or do i round my results to 3 figures because 3 is the least precise number in the original problem?

Update:

to make things simpler

.21 or .207?

Relevance

The original problem has one number with 3 significant digits and two with 4.

The fact that when you subtract the two numbers with 4 significant digits you get a result with two significant digits doesn't reduce the number of significant digits in the original numbers. Those are the ones that matter.

The 0.025 value isn't the determining value for counting significant digits; the original 8.27 value is. Since it has three significant digits, so should your answer. Your answer should be 0.207

• Anonymous