What have you done so far ?
Example, no error checking:
Imports System
Module Program
Sub Main(args As String())
Dim USD As Decimal
Dim Rate As Decimal
Console.Write("How many US Dollars ? ")
USD = CDec(Console.ReadLine)
Console.WriteLine()
Console.Write("What is the Conversion Rate ? ")
Rate = CDec(Console.ReadLine)
Console.WriteLine()
Console.WriteLine(USD.ToString & " US Dollats = " & (Rate * USD).ToString & " Canadian Dollars")
Console.WriteLine("ENTER to exit")
Console.ReadLine()
End Sub
End Module