To what decimal place should each answer be rounded? How many significant figures does the rounded answer have? A. 9 cm+2.8 cm=11.8 cm (unrounded) A. 9 cm+2.8 cm=11.8 cm (unrounded) After rounding, the number should be reported to the tenths place. ones place. hundredths place. Thus, the number has 2 significant figures. 1 significant figure. 3 significant figures. B. 0.135 atm+0.6 atm=0.735 atm (unrounded) B. 0.135 atm+0.6 atm=0.735 atm (unrounded) After rounding, the number should be reported to the ones place. tenths place. hundredths place. Thus, the number has 2 significant figures. 1 significant figure. 3 significant figures.

a) rounded to the ones place and 2 significant figures.

b) rounded to tenths place and 1 significant figure.

Step-by-step explanation:

Significant figures are the number of needed place values for accuracy. Round each number according to the least number of significant figures within the problem.

A. 9 cm+2.8 cm = 11.8 cm rounds to 12 which has 2 significant figures. Round to the ones place value since 9 has the least number of significant figures.

B. 0.135 atm+0.6 atm = 0.735 atm rounds to 0.7 atm which has 1 significant figure. Zero preceding the value is not considered significant. Round to the tenths place value since 0.6 has the least number of significant figures.