What is the final answer of 2.169/0.68?

1 Answer
Jun 9, 2018

#2.169/0.68=3.2#, with two significant digits.

Explanation:

This is a prolem of sinificant digits. Remember the following rules for arithmetic with significant digits:

1) When adding or subtracting, round to the smallest power of 10 where both numbers have significant digits. Thus #2.169-0.68=0.49#, not #0.489#, because #2.169# has a significant digit in the thousandth place but #0.68# has a significant digit only in the hundredths place.

2) When multiplying or dividing, roundbto the lowest number of significant digits of the two numbers. Thus #2.169/0.68=3.2# because #2.169# has four significant digits but #0.68# has only two.

If we meant for #0.68# to be accurate to four significant digits we would have rendered it as #0.6800#, counting the "extra zeroes after the decimal point as additional significant digits.