estimate the range for the sum 9.65+30.1+5.835

Answer 1

are you looking for something like:

9.5 + 30 + 5.5 < 9.65+30.1+5.835 < 10 + 30 + 6
45 < 9.65+30.1+5.835 < 46

so the sum is between 45 and 46