I'm with you, elh0706. The only thing we can do with MrWiggly at times is that exact same approach. Funny thing is that once you stop responding with the correct answer he typically "discovers" for himself that the other person was right.
I have also found that it just is not worth the effort to get into the power struggles over most issues that MrWiggly argues about. I typically respond with "fine, if that's you believe to be correct" or something along those lines and let it go. Unless it's a parenting issue that requires me to stand firm!
We've also taken some opportunities like this to discuss the difference between fact and opinion. So sometimes we actually are expressing and debating opinions now instead of arguing about a math fact.
