I can't answer your math question, that wasn't taught in the "guzintas" classes I took. But I guess it goes inta the ledger and comes out as a divine dividend, but I'm no math genius so that's just a guess.
We've never in all our years filed electronically nor had a direct deposit refund so to the best of my knowledge that don't have in their records any bank account tied to our IRS records. Maybe at some point we'll get a paper check but if we do we won't be cashing it, or we might just cash it and donate the money to the church food bank.
On second thought, signing the check over to the church would be a better option, that way there could be no chance that we didn't donate it. Yes, I like that approach better. See you are helping me get my ducks in row and didn't even know it. Thanks.