regifting robin

I got this question. How does this game work? Really, this is one of those silly things that gets forwarded a lot. It is called Regifting Robin. The basic idea is: pick a 2 digit number, like 37 subtract both the number in the tens place and the number in the ones place from the original number find the number you have left on a grid of "gifts" and robin will guess what your gift was You may have seen stuff like this before and figured it out. It really isn't too bad as long as you know two things (one is a trick) In a two digit number, like 37, the number is really 3*10 + 7*1. I know…