I’ve learned this new game that is quite addicting. It’s called ‘Nim.’ You take 16 objects (I use cards) and put them in rows of 1-3-5-7 in a pyramid shape like so:
1 – Row 1
3 3 3 – Row 2
5 5 5 5 5 – Row 3
7 7 7 7 7 7 7 – Row 4

Grab someone to play with, and take turns taking as many cards from a single row as you want. For example:

You take one card from row 1;
Partner takes three cards from row 3;
You take all of the cards from row 4;

and so on. This continues until someone draws the last card. The person who draws the last card loses.

There is a long wikipedia article about it, as well as several mathematical theorems for the game. But you can easily, by playing several games, develop your own strategies, scenarios, and theorems. This game was introduced to us my one of our teachers at school two weeks ago, and has spread like wildfire across the student body. Not to brag or anything, but I have gotten pretty good at the game (because I play it all the time!), so I expect to be challenged by you all if you visit us!