Stumped. Aug 28, 2008 | Magic | 4 comments Ok, you see a lot of these tricky sites on the www. But this… this is no run of the mill sawing off legs. Do this and tell me how he does it. I’m thinking magic. Previous Post Next Post 4 Comments Robert on August 28, 2008 at 5:06 pm If you and Hal are stumped, I don’t feel so stupid. Reply Arp on August 28, 2008 at 5:23 pm There’s got to be limited combinations of numbers that result from the first part. I think something like 16 or so results. So take those 16 possible answers, reverse & subtract. Another 16 answers. Remove the zeros and there’s the possible results. I can’t sit down to do it, but I’m guessing the results are limited. Reply Chuck Smith on August 29, 2008 at 11:18 pm I tried three different combinations and noticed that after the subtraction, the resulting digits always added up to 9 (sometimes you have to keep adding until you’re down to a single digit, but that single digit was always 9). Now if you give me two or three digits, then I just add them together and subtract that from 9, and that tells me the one that’s missing. (I’m not going to submit this as a formal proof, but I think I’m heading in the right general direction of the answer.) …Chuck Reply Saratica on August 30, 2008 at 9:00 am Ok, Arp, Chuck wins the Rainman of the Day award. You wouldn’t happen to know anything about counting cards, would you, Chuck? Reply Submit a Comment Cancel replyYour email address will not be published. Required fields are marked *Comment Name * Email * Website Save my name, email, and website in this browser for the next time I comment.