Умножение в DataGrid

Private Sub myDataGridView2_CellContentClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles myDataGridView2.CellContentClick
 
 
"Column4" = "Column2" x "Column3"
Next Row 
 
    End Sub

For i As Integer = 0 To Me.DataGridView1.RowCount - 1
            If IsDBNull(Me.DataGridView1.Item(2, i).Value) = False And IsDBNull(Me.DataGridView1.Item(2, i).Value) = False Then
                Me.DataGridView1.Item(4, i).Value = CDbl(Me.DataGridView1.Item(2, i).Value) * CDbl(Me.DataGridView1.Item(3, i).Value)
            End If
        Next

 If IsDBNull(myDataGridView2.Item(i, 2).Value) = False And IsDBNull(myDataGridView2.Item(i, 3).Value) = False Then

myDataGridView2.Item(i, 4).Value = CDbl(myDataGridView2.Item(i, 2).Value) * CDbl(myDataGridView2.Item(i, 3).Value)

myDataGridView2.Item(3, i).Value=..............

myDataGridView2.Item(4, i).Value=..............

Imports System.Data
 
Public Class Form1
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim dataSet As New DataSet()
        Dim dataTable As New DataTable("table")
        dataTable.Columns.Add("name", Type.GetType("System.String"))
        dataTable.Columns.Add("price", Type.GetType("System.Double"))
        dataTable.Columns.Add("count", Type.GetType("System.Double"))
        dataTable.Columns.Add("sum", Type.GetType("System.Double"), "price*count")
        dataSet.Tables.Add(dataTable)
        Dim grid As New DataGridView()
        Dim bindingSourse As New BindingSource(dataSet, "table")
        grid.DataSource = bindingSourse
        Me.Width = 500
        grid.Width = 400
        Me.Controls.Add(grid)
    End Sub
End Class