Round off each number to three significant figures.
a. 1.2735 b. 0.002 536 22 c. 3,836.9
Analysis
If the answer is to have three significant figures, look at the fourth number from the left. If this number is 4 or less, drop it and all remaining numbers to the right. If the fourth number from the left is 5 or greater, round the number up by adding one to the third nonzero digit.