When calculating significant digits, it is necessary to use proper rounding
The rules of rounding are:
a. Round only the final answer.
b. Carry extra digits on intermediate calculations.
c. Consider only one digit past the last significant digit to determine
how to round the last digit.
d. The digit to the right of 5 rounds to an even number.
*3.548 rounds to 3.5. (Ignore the 8, just
consider the 4. The 5 remains unchanged.)
*3.758 rounds to 3.8. (Ignore the 8, Since
5 rounds to even, the 7 rounds to 8.)
*3.458 rounds to 3.4. (Since rounds to even,
the 4 remains because it is even.)