If you don't mind me asking, why are you so convinced the holocaust actually DID occur as described? Also, which figure (if any) of the several conflicting numbers of Jewish dead do you think is the most accurate, and why?
Good luck getting him to show the "math" because they know it just doesn't make sense. Instead, all they can do is appeal to the "sob story" side of things with maybe some pictures of some dead bodies thrown in for good measure, but do the "math" Nope, the numbers just don't add up. They can't allow people to apply logic. That's why they've managed to get laws in place around the world to make it a crime to even "question" the math because they know it'll never add up and the more time goes on the more preposterous their claims become.