C# - How To Sort The Grid View Whose Column Is Listing Integers

I am sorting the grid using DataView's "Sort" property. I am passing sort expression and the order in which the grid is to be sorted(ASC or DESC). But the problem is, since the column on which I am sorting the grid is listing the intergers, the sorting is happening as if it is a string. But I need integer sorting rather string sorting on that column.

The grid displays below as ascending order(string sorting)
55
77
8

But I need the columns to be displayed like this(Integer sorting)
8
55
77