Auto Addition of Number in Windows Form

Question

Sir I am now in a Program of Student Mark Details.

Here my form:-


You can see name ,teMark,ceMark , peMark, and total in the DataGrid Coulmn.

in this grid, I set grid property of allow to add column to true.

My task is when I enter teMark, the this mark to be added to the total Column, when I enter ceMark, i want incrementation of column total to total of two column. like that I want the total of all columns in that column total.

please help me in this topic