In leveling work, the rise and fall method consists of determining the difference of elevation between consecutive points by comparing each point after the first that immediately preceding it. The difference between there staff reading indicates a rise fall according to the staff reading at the point. The R.L is then found adding the rise or subtracting the fall from the reduced level of preceding point. For arithmetic check it includes back sight, intermediate sight and fore sight. Sum of B.S. - sum of F. S. = sum of rise - sum of fall = last R. L. - first R.L Where, Intermediate sight (IS): all readings taken between a BS and a FS.