How to create Simple Calculations using Active-X DLL in Visual Basic

To Calculate PNR value and Celsius to Fahrenheit by using Active-X DLL in VB.
PROCEDURE and a Logarithm

Source Code Programming in Visual Basic
Part – 1
Public Function si(a As Integer, b As Integer, c As Integer)
si = (a * b * c) / 100
End Function
Public Function celsius(a As Integer)
c = (f-32) * (5/9)
End Function
Public Function fahrenheit(a As Integer)
f = (1.8 * c) + 32
End Function
Module Coding:
Sub Main()
End Sub
Part-2
Dim A As New Class1
Private Sub Command1_Click()
Text4.Text = A.si(Val(Text1.Text), Val(Text2.Text), Val(Text3.Text))
End Sub
Private Sub Command2_Click()
Text6.Text = A.celsius(Val(Text5.Text))
End Sub
Private Sub Command3_Click()
Text8.Text = A.fahrenheit (Val(Text7.Text))
End Sub
To Calculate PNR value and Celsius to Fahrenheit Source Code programming