C#

decimal jumlah=0;
            int x, y;
            for (x = 1; x < this.dgPendTbl1.ColumnCount; x++)
            {
                for (y = 0; y < this.dgPendTbl1.RowCount - 1; y++)
                {
                    if(this.dgPendTbl1[x,y].Value!=null)
                        jumlah += decimal.Parse(this.dgPendTbl1[x, y].Value.ToString());
                }
                int rowcount = this.dgPendTbl1.RowCount;
                this.dgPendTbl1[x, rowcount - 1].Value = jumlah.ToString();
                if (x == 2 || x == 4) this.dgPendTbl1[x, rowcount - 1].Value = (Math.Round(jumlah,2)).ToString();
                jumlah = 0;
            }

Public Function changeNum(ByVal Number As Double) As Double
    Dim numDouble As Double
    Dim num As String
    Dim TestArray() As String = Split(Number.ToString(), ".")
    num = TestArray(1) + "." + TestArray(0)
    numDouble = CDbl(num)
    Return numDouble
End Function

Dim testnum As Double = changeNum(12.5)