How to round off a number if the last digit is smaller than 5?
If the digit immediately to the right of the last sig. fig. is less than 5, you round down.
35.76 in 3 significant figure. is 35.8 (round up because it is more than half-way between 35.7 and 35.8)
35.74 in 3 significant figure is 35.7 (round down because it is less than half-way between 35.7 and 35.8)