Can't wait to try this "magic trick" with my 1st and 2nd graders next week. We did a magic trick earlier this winter and they thought that they really were magicians! I found these magic cards in a kit, but there were multiple addends that had sums that went up to 62. Much too hard for the kiddos I work with. I simplified it to this document Math Magic, I think the math is manageable with 1st or 2nd grade.
Note: this is the first time I ever shared a document through Google Drive. Please let me know if you have any difficulties!