How is a numerical value rounded off ?

Explanation

A numerical value is rounded off as follows :
(i) If the digit to be rounded off is less than 5, then the preceding digit is not changed. For example, when `4.54` is rounded off to two significant figures, the value will be `4.5`.
(ii) If the digit to be rounded off is greater than 5, then the preceding digit is raised by 1. For example, in rounding off `4.57` to two significant figures the result will be `4.6`.
(iii) If the digit to berounded off is 5, then
(a) preceding digit is not changed, if it is even. For example, when `8.65` is rounded off to two significant figures, then the result will be `8.6`.
(b) preceding digit is raised by 1, if it is odd. For example, when `8.75` is rounded off to two significant digits then the result will be `8.8`.