summation in datagridview

DataGridView1.RowCount = 9
        For i As Integer = 1 To 7
            DataGridView1.Rows(i).Cells(0).Value = i
        Next
        Dim kq1 As Integer = 0
        Dim kq2 As Integer = 0
        Dim kq3 As Integer = 0
        Dim kq4 As Integer = 0
        Dim kq5 As Integer = 0
        Dim kq6 As Integer = 0
        Dim kq7 As Integer = 0
        Dim a As Integer = DataGridView1.Rows(0).Cells(0).Value
        Dim b As Integer = DataGridView1.Rows(1).Cells(0).Value
        Dim c As Integer = DataGridView1.Rows(2).Cells(0).Value
        Dim d As Integer = DataGridView1.Rows(3).Cells(0).Value
        Dim e1 As Integer = DataGridView1.Rows(4).Cells(0).Value
        Dim f As Integer = DataGridView1.Rows(5).Cells(0).Value
        Dim g As Integer = DataGridView1.Rows(6).Cells(0).Value
        kq1 = a + b
        kq2 = c + kq1
        kq3 = d + kq2
        kq4 = e1 + kq3
        kq5 = f + kq4
        kq6 = g + kq5
        DataGridView1.Rows(0).Cells(0).Value = kq1
        DataGridView1.Rows(1).Cells(0).Value = kq2
        DataGridView1.Rows(2).Cells(0).Value = kq3
        DataGridView1.Rows(3).Cells(0).Value = kq4
        DataGridView1.Rows(4).Cells(0).Value = kq5
        DataGridView1.Rows(5).Cells(0).Value = kq6