Games

Answer to yesterday’s Guess That Estimation:

The average person will eat 10,000 chocolate bars in a lifetime.

Today’s Activity:

Nim is fun, challenging, and rewarding for a wide range of kids. Done right, it can engage everyone from Kindergarten to upper elementary kids, and connect to basic counting, and arithmetic up to division. Completely unlocking the game is an exciting and powerful achievement for a student.

Materials Required: Counters (example: coins, beans, pieces of paper, pebbles)

How to Play:

Nim is a two-player game. You start with a pile of counters. On your turn, remove one or two counters from the pile. You must take at least one token on your turn, but you may not take more than two. Whoever takes the last token is the winner.

Example Game:

We start with 8 counters in the pile.
Player 1 takes one counter, leaving 7.
Player 2 takes two counters, leaving 5.
Player 1 takes one counter, leaving 4.
Player 2 takes one counter, leaving 3.
Player 1 takes one counter, leaving 2.
Player 2 takes two counters, leaving 0 and winning the game.

Variations

  1. Change the size of the pile.
  2. 1-2-3 Nim: players may take one, two, or three counters per turn.

Questions

The Central Question: how can you win 1-2 Nim? What would a perfect strategy look like?

Good questions to ask:

  • What move should I make?
  • How did you/I win that game?
  • What do you think your/my opponent will do if you/I take two counters?
  • Would you like to take back your move?
  • What have you noticed about this game?

References: http://wordplay.blogs.nytimes.com/2011/06/13/numberplay-1-2-nim/