30 is between two perfect squares of 25 and 36 and so we can be sure that square root of 30 lies between 5 and 6
Now the difference of 36 and 25 is 11.So we may say that for a difference of 11 units,there is a change of 1 in the value of the square rootl
Now,find the difference of 30 and 25,the square of 25.It is 5
So square root of 30 would be approaximately 5 plus 5/11
or 5+0.455=5.46 approaximately
