Private Sub Command1_Click()
Label1.Caption = Val(TextBox1.Text) + Val(TextBox2.Text)
End Sub
Private Sub Command2_Click()
Label1.Caption = Val(TextBox1.Text) * Val(TextBox2.Text)
End Sub
Private Sub Command3_Click()
Label1.Caption = Val(TextBox1.Text) - Val(TextBox2.Text)
End Sub
Private Sub Command4_Click()
Label1.Caption = Val(TextBox1.Text) / Val(TextBox2.Text)
End Sub
Private Sub Command5_Click()
Label1.Caption = Sin(TextBox1.Text)
End Sub
Private Sub Command6_Click()
Label1.Caption = Sqr(TextBox1.Text)
End Sub
======================
Private Sub Command1_Click()
Label1.Caption = Left(TextBox1.Text)
End Sub
Private Sub Command2_Click()
Label1.Caption = Right(TextBox1.Text)
End Sub
Private Sub Command3_Click()
Label1.Caption = Mid(TextBox1.Text, 1) 'Например
End Sub
Private Sub Command4_Click()
Label1.Caption = Len(TextBox1.Text)
End Sub
Private Sub Command5_Click()
Label1.Caption = Asc(TextBox1.Text)
End Sub
Private Sub Command6_Click()
Label1.Caption = Chr(Val(TextBox1.Text))
End Sub
======================
Dim S As String, N As Byte
Private Sub Command1_Click()
Label1.Caption = ""
N = 1
Do While N <= Len(TextBox1.Text)
S = Mid(TextBox1.Text, N, 1)
Label1.Caption = S + Label1.Caption
N = N + 1
Loop 
End Sub