Sub ThreeNumbers()
Dim num1 As Integer, num2 As Integer, num3 As Integer
num1 = 10
num2 = 20
num3 = 30
MsgBox MyAverage(num1, num2, num3)
MsgBox num1
MsgBox num2
MsgBox num3
End Sub
Function MyAverage(ByVal num1, ByVal num2, ByVal num3)
num1 = num1 + 1
MyAverage = (num1 + num2 + num3) / 3
End Function