Syntax error when multiplying variables in VB.NET - vb.net

Question

I'm trying to multiply two variables within VB Studio, however I am getting a syntax error when trying to do this.
(Quantity * ItemCost) gives me a syntax error on the first bracket, and removing the brackets gives me the error that method arguments must be enclosed in parenthesis.
Sorry if this was rather vague or really obvious, I am new to programming in general and am doing my best to make simple programs. I know my code is far from the most efficient but it's the best I can do at the moment.
The whole of my code is below :
Public Class Form1
Dim CustomerName As String
Dim Pensioner As Boolean
Dim Takeout As Boolean
Dim Items(4) As Array
Dim CostOfItems(4) As Array
Dim Alpha As Integer = 0
Dim Quantity As Integer
Dim ItemCost As Integer
Private Sub txtName_TextChanged(sender As Object, e As EventArgs) Handles txtName.TextChanged
CustomerName = txtName.Text
End Sub
Private Sub cboItemName_SelectedIndexChanged(sender As Object, e As EventArgs) Handles cboItemName.SelectedIndexChanged
If cboItemName.Text = "Tea" Then
txtItemPrice.Text = "£0.50"
ElseIf cboItemName.Text = "Coffee" Then
txtItemPrice.Text = "£0.70"
ElseIf cboItemName.Text = "Orange Juice" Then
txtItemPrice.Text = "£0.80"
ElseIf cboItemName.Text = "Apple Juice" Then
txtItemPrice.Text = "£0.80"
ElseIf cboItemName.Text = "Potato" Then
txtItemPrice.Text = "£1.00"
End If
ItemCost = txtItemPrice.Text
End Sub
Private Sub txtQuantity_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtQuantity.KeyPress
If Asc(e.KeyChar) <> 8 Then
If Asc(e.KeyChar) < 48 Or Asc(e.KeyChar) > 57 Then
e.Handled = True
End If
End If
Quantity = txtQuantity.Text
End Sub
Private Sub btnNext_Click(sender As Object, e As EventArgs) Handles btnNext.Click
If chxPension.Checked = True Then
Pensioner = True
chxPension.Hide()
End If
If cbxTakeOut.Checked = True Then
TakeOut = True
cbxTakeOut.Hide()
End If
Quantity * ItemCost
txtQuantity.Text = ""
cboItemName.Text = ""
Alpha += 1
txtName.ReadOnly = True
End Sub
End Class
(I have now changed the ItemCost value to not include a £ or . , however I am still getting a syntax error on the bracket)

Answer 1

The problem with your code is that you are not assigning the result of the multiplication to any variable. Some languages permit that (calculating a value and throwing it away), but apparently VB.NET doesn't. It is trying to save you from a common programmer mistake.
Do it like this instead:
Dim TotalCost As Integer = Quantity * ItemCost
The result of the multiplication will now be stored in the variable TotalCost, which you can use for whatever you need.
Of course, you could also store the result of the calculation in one of the operand variables (assuming, of course, it is not a constant). In this case, judging from the names of the variables, it doesn't make much sense, but sometimes it is appropriate:
ItemCost = Quantity * ItemCost ' probably wrong, but syntactically legal

Answer 2

You also need to declare your variables correctly.
item cost can not be integer.
Item cost should be something like double or decimal
Dim TotalCost as Decimal = Quantity * ItemCost

Answer 3

Could you please remove the £ in your txtItemPrice.Text?
Replace this in your existing codes:
ItemCost = cInt(txtItemPrice.Text)
Quantity = cInt(txtQuantity.Text)
This is to convert the Strings (.text) into Integer
For the computation of Total Cost:
Dim Total As Integer = Quantity * ItemCost
Please Take Note:
Integer data types cannot hold values with decimal. Use Double instead.