You need to be able to express the result of any calculation to the appropriate number of significant digits for the rest of the course. Significant digits are all the digits in a measurement that are certain, plus the first one that is uncertain. Consult your text, p.17-22.
Homework: p.24 #2, 3, 5; p.22 #3
Homework: p.24 #2, 3, 5; p.22 #3