Visual basic program to create calculator with extra two button for factorial and check even/odd.

Design window :- Take button on form and one textbox on form and make it place as shown below and then in code window of each button do following coding. Dim operand1 As Double Dim operand2 As Double Dim operator As String Private Sub Command1_Click() Text1.Text = Text1.Text + "1" End Sub Private Sub Command2_Click() Text1.Text = Text1.Text + "2" End Sub Private Sub Command3_Click() Text1.Text = Text1.Text + "3" End Sub Private Sub Command4_Click() Text1.Text = Text1.Text + "4" End Sub Private Sub Command5_Click() Text1.Text = Text1.Text + "5" End Sub Private Sub Command6_Click() Text1.Text = Text1.Text + "6" End Sub Private Sub Command7_Click() Text1.Text = Text1.Text + "7" End Sub Private Sub Command8_Click() Text1.Text = Text1.Text + "8" End Sub Private Sub Command9_Click() Text1.Text = Text1.Text + "9" End Sub Private Sub Command10_Click() ...