vending machine code. how to calculate change? - vb.net

Question

I'm trying to write a program for a vending machine. The program will ask the user to pick an option and it will calculate the change depending on the amount entered and the price of the product.
I can't get the program to calculate the change. I tried this but it doesn't work
Select Case choice
Case "1"
Console.WriteLine("enter amount")
amount = Console.ReadLine()
If amount < 0.6 Then
Console.WriteLine("not enough")
Else
change = amount - 0.6
End If
full code
Dim choice As String
Dim amount As Integer
Dim change As Integer
Sub Main(args As String())
Console.WriteLine("option 1: snickers price = 60p")
Console.WriteLine("option 2: coke price = £1")
Console.WriteLine("option 3")
Console.WriteLine("option 3")
Console.WriteLine("option 4")
Console.WriteLine("option 5")
Console.WriteLine("option 6")
Console.WriteLine("option 7")
Console.WriteLine("option 8")
Console.WriteLine("option 9")
Console.WriteLine("option 10")
choice = Console.ReadLine()
Select Case choice
Case "1"
Console.WriteLine("enter amount")
amount = Console.ReadLine()
If amount < 0.6 Then
Console.WriteLine("not enough")
Else
change = amount - 0.6
End If
Case "2"
Console.WriteLine("enter amount")
amount = Console.ReadLine()
If amount < 1 Then
Console.WriteLine("not enough")
Else
change = amount - 1
End If
End Select
Console.ReadLine()
End Sub

Answer 1

I see two issues in your code:
You are using Integer type for data that is decimal, so first of all you need to change the first two variables to Double
You are never showing the value that Change has; you calculate it but it is never shown on the screen. I have added a line that shows the change only if it is greater than 0.
Try something similar to the code I show below and see if you can continue from there:
Sub Main()
Dim choice As String
Dim amount As Double
Dim change As Double
Console.WriteLine("option 1: snickers price = 60p")
Console.WriteLine("option 2: coke price = £1")
Console.WriteLine("option 3")
Console.WriteLine("option 3")
Console.WriteLine("option 4")
Console.WriteLine("option 5")
Console.WriteLine("option 6")
Console.WriteLine("option 7")
Console.WriteLine("option 8")
Console.WriteLine("option 9")
Console.WriteLine("option 10")
choice = Console.ReadLine()
Select Case choice
Case "1"
Console.WriteLine("enter amount")
amount = Console.ReadLine()
If amount < 0.6 Then
Console.WriteLine("not enough")
Else
change = amount - 0.6
End If
Case "2"
Console.WriteLine("enter amount")
amount = Console.ReadLine()
If amount < 1 Then
Console.WriteLine("not enough")
Else
change = amount - 1
End If
End Select
If change > 0 then
Console.WriteLine("Change: " & change)
End If
End Sub