Question

You calculate the following answer to a problem: 12.655 cm. You are asked to round your answer to four significant figures. Which answer is correct?

a. 12.66 cm
b. 12.65 cm
c. 12.60 cm
d. 12.70 cm

Answer 1

the answer is A. to the question

Answer 2

Significant figures basically means you have x digits from the first digit that is not a 0.
Since 12.655 doesn't start with a zero we start counting from the 1, and 4 figures takes us to 12.65. However the digit after that is a 5 so we round it up to 12.66.

Therefore the answer is A.