To what decimal place should each answer be rounded? and how many significant figures does the rounded answer have?

a) 9cm + 2.8 cm= 11.8cm (unrounded)

b) 0.135 atm + 0.6 atm= 0.735 atm (unrounded)

PLEASE HELP

2 answers

I gave you a link earlier. What trouble are you having?
a. 11.8 is rounded to ones place and thus has 2 significant figures
B. 0.735 is rounded to tenth place and has one significant figures