Private Sub btnComputePrice_Click(…) Handles _
                           btnComputePrice.Click
   Dim quantity As Integer = CInt(txtOrangeQuantity.Text)
   Dim orange_price As Double = 4.5
   ComputePrice(quantity)
   
End Sub

Sub ComputePrice (ByVal qty as Integer)
' Calculate the price
 Dim price = orange_price * ???  
 txtPrice.Text= CStr(Math.Round(???,2)) ' Computed value shown on text box
End Sub