Rules of rounding off

 Rounding off the uncertain digit : 

(a) If the left most digit to be rounded off is more than 5 , the preceding number is increased by one. 

Example : 2.16 is rounded to 2.2

 (b) If the left most digit to be rounded off is less than 5 , the preceding number is retained.

 Example : 2.14 is rounded off to 2.1 

(c) If the left most digit to be rounded off is equal to 5 , the preceding number is not changed if it is even and increased by one if it is odd. Example : 3.25 is rounded off to 3.2 2.35 is round off to 2.4