Need assistance with adding and multiplying from a listbox

Trying to build a calculator for a class assignment that adds numbers from a user input listbox also have a multiply button, below is my code but no matter what I change the math does not seem to work. Any assistance would be greatly appreciated.

Public Class ArithmeticCalculator

Private Property operands As Integer

Private Sub enterButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles enterButton.Click

Dim operand As Integer
If enterOperandTextBox.Text <> String.Empty Then
OperandsListBox1.Items.Add(enterOperandTextBox.Text)
OperandsListBox1.ClearSelected()
enterOperandTextBox.Clear()
End If

operand = 0

If OperandsListBox1.Items.Count = 0 Then
enterButton.Enabled = True
addButton.Enabled = False
multiplyButton.Enabled = False
End If

End Sub
Private Sub addButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles addButton.Click
Dim result As Integer
Dim operandCounter As Integer

result = 0
operandCounter = 0

Do While operandCounter < OperandsListBox1.Items.Count
result = OperandsListBox1.Items(operands)
result += operands
operandCounter += 1
Loop
If operandCounter <> 0 Then result = result + OperandsListBox1.Items.Count
resultLabel.Text = result


End Sub
Private Sub multiplyButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles multiplyButton.Click
Dim result As Integer
Dim operandCounter As Integer

result = 0
operandCounter = 0

Do While operandCounter < OperandsListBox1.Items.Count
result = OperandsListBox1.Items(operands)
result += operands
operandCounter += 1
Loop
If operandCounter <> 0 Then result = result * OperandsListBox1.Items.Count
resultLabel.Text = result


End Sub


End Class