Question

In which of the following calculations is there more than one significant figure in the answer?

123 times 89

8.85 plus 1.11

15.2 divided by 30.3

8 minus 2.55

Answer 1

the answer is the last one

let's recall the rules for significant figures. 

for multiplication and division, you round to the least significant figures.

for addition and subtraction, you round to the least places after the decimal. 

1. 123 x 89= 10947, multiplication- since you have to round to the least sig figs, which is 2, the answer rounds to 11000

2. 8.85 + 1.11= 9.96, addition- since you have round to the least places after the decimal, which is 2, the answer rounds to 9.96

3. 15.2 / 30.3= 0.50165017, division- round to 3 sig figs, 0.502

8 -  2.55= 5.45, subtraction, least places after the decimal, which is none because of the whole number 8. the answer is 5.