Untitled

Can we make the below Datatable subtraction method as generic
private DataTable DtSubtract(DataTable dt, int insertAt)
{
    DataRow dr;
    List<object> lstColumnSummation = new List<object>();
    double res = 0;

    for (int i = 0; i < dt.Columns.Count; i++)
    {
    for (int row = 0; row < dt.Rows.Count; row++)
        res = Convert.ToDouble(dt.Rows[row][i]) - res;

    lstColumnSummation.Add(-(res));
    res = 0;
    }
    //add a new data row
    dr = dt.NewRow();
    dr.ItemArray = lstColumnSummation.ToArray();
    //insert the row at the position specified
    dt.Rows.InsertAt(dr, insertAt);
    //accept the changes
    dt.AcceptChanges();
    return dt;
}

First is: double res = 0; TO int res = 0;

Second is:   res = Convert.ToDouble(dt.Rows[row][i]) - res; TO res = Convert.ToInt32(dt.Rows[row][i]) - res;