Discussing strategy with games is a great way to engage students in talking about their reasoning.  We often use games in math class. We can engage our students in  productive discussions if we have students work together to consider next best moves.

Nancy Anderson recently taught this simple but flexible game at an ATMIM  meeting in January.  Once we understood the game she had us think about the next best move for a particular scenario.

I am calling the game “Guess My Problem”.  It’s like Hangman, only it’s about making math equations.

Here is an example of how you could play it with 2 digit + 2 digit addition equations.

“Guess My Problem” (Like “Hangman”)

Try to use as few moves as you can.

Player 1 writes down the equation with blanks and the list of digits.

Ex. __ __ + __ __ = __ __

Player 1 records the equations with numbers in a hidden place.

As Player 2 guesses digits, player 1 fills in the blanks guessed correctly and keeps track of the numbers tried and the numbers eliminated.

So here is where we can start thinking about strategy:

After 3 moves, one game looked like this with two digits left to be placed:

1  __+­ ­­­­__ 1 = ­­­ ­44      Correct Guesses             Numbers Eliminated

1,  4                                           7

What is the best digit to guess next? Why?

 Challenge students to reason as a class about best moves.  Play it with larger numbers or different operations.  I’d love to see parents playing this with their children as they wait in a restaurant or for an appointment!

Thanks to Nancy Anderson, co-author of Classroom Discussions in Math,  for teaching this at ATMIM in January.