I can't seem to set an object variable to an integer or single whose value is zero

[jmcilhinney]

If it's not working then you're doing it wrong. As you haven't actually shown us what you're doing, we can't tell you what's wrong with it. If you run this code you'll see that there's no way that you should be getting a NullReferenceException when puling an Integer or Single from an Object variable, even if you have in fact assigned Nothing to the variable.

Module Module1
 
    Sub Main()
        Dim number As Object
 
        number = Nothing
        Console.WriteLine(CInt(number))
        number = 123
        Console.WriteLine(CInt(number))
        number = 0
        Console.WriteLine(CInt(number))
        number = 456
        Console.WriteLine(CInt(number))
        number = Nothing
        Console.WriteLine(CInt(number))
 
        number = Nothing
        Console.WriteLine(CSng(number))
        number = 12.34F
        Console.WriteLine(CSng(number))
        number = 0.0F
        Console.WriteLine(CSng(number))
        number = 56.78F
        Console.WriteLine(CSng(number))
        number = Nothing
        Console.WriteLine(CSng(number))
 
        Console.ReadLine()
    End Sub
 
End Module

As I said, Nothing corresponds to zero for numeric types so if you convert a null reference to a numeric type then you get zero.

If you're always going to be storing an Integer or a Single then why not just declare the variable as type Single? You'll always be able to store an Integer in it. If you want to be able to distinguish a value that should be an Integer rather than a Single then use a Boolean flag. You'd need that when using Object anyway. Also, if you actually use a value type then you could declare it as nullable, which would then allow you to distinguish between zero and no value.