This document contains the code for a basic calculator application. It includes code to handle button clicks that add numbers and operators to a text box. There is also code to evaluate the calculation based on the selected operator when the equals button is clicked. The text box is cleared after numbers are assigned to variables for the first and second operands or the operation is set.

1. CALCULADORA
Public Class Form1
Dim n1, n2 As Integer
Dim oper As Char
Private Sub Button14_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
TextBox1.Text &= 8
End Sub
Private Sub Button9_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
TextBox1.Text &= "/"
End Sub
Private Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
TextBox1.Text &= 5
End Sub
Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
TextBox1.TextChanged
End Sub
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 Button11_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button11.Click
TextBox1.Text = TextBox1.Text & 2
End Sub
Private Sub Button10_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button10.Click
TextBox1.Text = TextBox1.Text & 3
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button3.Click
TextBox1.Text = TextBox1.Text & 4
End Sub
Private Sub Button7_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button7.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 Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button2.Click
TextBox1.Text = TextBox1.Text & 7
End Sub
Private Sub Button18_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button18.Click
TextBox1.Text = TextBox1.Text & 8
End Sub

2. Private Sub Button13_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button13.Click
TextBox1.Text = TextBox1.Text & 9
End Sub
Private Sub Button12_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button12.Click
TextBox1.Text = TextBox1.Text & 0
End Sub
Private Sub Xy_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Xy.Click
TextBox1.Text = TextBox1.Text & "."
End Sub
Private Sub Button15_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button15.Click
If IsNumeric(TextBox1.Text) Then
n2 = Val(TextBox1.Text)
Else
n2 = 0
If oper = "/" Then
n2 = 1
End If
End If
Select Case (oper)
Case "+"
TextBox1.Text = n1 + n2
Case "-"
TextBox1.Text = n1 - n2
Case "*"
TextBox1.Text = n1 * n2
Case "/"
TextBox1.Text = n1 / n2
Case "%"
TextBox1.Text = n1 * (n2 / 100)
Case "pow"
TextBox1.Text = n1 ^ n2
Case "sqr"
Math.Sqrt(n1)
End Select
End Sub
Private Sub Button9_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button9.Click
n1 = Val(TextBox1.Text)
oper = "/"
TextBox1.Clear()
End Sub
Private Sub Button8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button8.Click
oper = ""
n1 = 0
n2 = 0
TextBox1.Clear()
End Sub
Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button5.Click
n1 = Val(TextBox1.Text)
oper = "*"
TextBox1.Clear()
End Sub
Private Sub Button16_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button16.Click
n1 = Val(TextBox1.Text)
oper = "+"
TextBox1.Clear()
End Sub
Private Sub Button14_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button14.Click
n1 = Val(TextBox1.Text)
oper = "-"

3. TextBox1.Clear()
End Sub
Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button4.Click
n1 = Val(TextBox1.Text)
oper = "pow"
TextBox1.Clear()
End Sub
Private Sub Button20_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button20.Click
End Sub
Private Sub Button19_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles
Button19.Click
n1 = Val(TextBox1.Text)
oper = "%"
TextBox1.Clear()
End Sub
End Class