Answer:
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.