Calculator

[mamrom]

I want to make one text box calculator will be responsible for the calculations and show them, for example: (7 + * 8 * 12 * 6) Have a second text box is responsible for calculation and display the answer, as the calculator of windows:


My problem the first text box records the number, and execution of the addition / subtraction / multiplication / division is not added to the text box but deletes the first number written down before performing mathematical operations.
* Of course the result is going good, but just I want to see your doing the first mathematical textbox1.
Here's the code:

Option Explicit On

Public Class Form1


    Dim FirstNumber As Single
    Dim SecondNumber As Single
    Dim AnswerNumber As Single
    Dim ArithmeticProcess As String

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        TextBox1.Text = TextBox1.Text + "1"
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        TextBox1.Text = TextBox1.Text + "2"
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        TextBox1.Text = TextBox1.Text + "3"
    End Sub

    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        TextBox1.Text = TextBox1.Text + "4"
    End Sub

    Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
        TextBox1.Text = TextBox1.Text + "5"
    End Sub

    Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button6.Click
        TextBox1.Text = TextBox1.Text + "6"
    End Sub

    Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button7.Click
        TextBox1.Text = TextBox1.Text + "7"
    End Sub

    Private Sub Button8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button8.Click
        TextBox1.Text = TextBox1.Text + "8"
    End Sub

    Private Sub Button9_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button9.Click
        TextBox1.Text = TextBox1.Text + "9"
    End Sub

    Private Sub Button10_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button10.Click
        TextBox1.Text = TextBox1.Text + "0"
    End Sub

    Private Sub Button11_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button11.Click
        TextBox1.Text = TextBox1.Text + "."
    End Sub



    Private Sub Button13_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button13.Click
        FirstNumber = Val(TextBox1.Text)

        TextBox1.Text = ""


        ArithmeticProcess = "+"

    End Sub

    Private Sub Button14_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button14.Click
        FirstNumber = Val(TextBox1.Text)
        TextBox1.Text = ""
        ArithmeticProcess = "-"
    End Sub

    Private Sub Button15_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button15.Click
        FirstNumber = Val(TextBox1.Text)


        TextBox1.Text = ""
        ArithmeticProcess = "X"
    End Sub

    Private Sub Button16_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button16.Click
        FirstNumber = Val(TextBox1.Text)
        TextBox1.Text = ""
        ArithmeticProcess = "/"
    End Sub

    Private Sub Button17_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button17.Click

        SecondNumber = Val(TextBox1.Text)

        If ArithmeticProcess = "+" Then
            AnswerNumber = FirstNumber + SecondNumber
        End If

        If ArithmeticProcess = "-" Then
            AnswerNumber = FirstNumber - SecondNumber
        End If

        If ArithmeticProcess = "X" Then
            AnswerNumber = FirstNumber * SecondNumber
        End If

        If ArithmeticProcess = "X" Then
            AnswerNumber = FirstNumber * SecondNumber
        End If
        If ArithmeticProcess = "/" Then

            AnswerNumber = FirstNumber / SecondNumber
        End If

        TextBox2.Text = AnswerNumber
        TextBox1.Text = ""
    End Sub

End Class