Rules for Rounding the Final Digit
There are two rules for determining what the final digit should be:
If the digit one beyond the required decimal place is 5 or over, then the digit at the final decimal place is rounded up.
4.908 to 2 decimal places is 4.91 The digit at the third decimal place is 8 therefore the digit at the second decimal place is rounded up from 0 to 1.
If the digit one beyond the required decimal place is less than 5, then the digit at the final decimal place remains the same.
5.652 to 2 decimal places is 5.65The digit at the third decimal place is 2 therefore the digit at the second decimal place remains the same.