Too Many Mice!

(MathPickle, 2012)

Your students need to add 15 and 17… How do you teach carrying from the ones column to the tens column?  This is the first of a series of games that will help.

“Too Many Mice” is a simple game in which students try to get as many mice as possible at the end of the game.  It was designed for the grade 2 teachers at Foundations for the Future Chartered Academy.

…too many mice is a two player game, but you can add an additional role:  one student can play the part of the cat.


1) If your students find the game is always won by the person who goes first, then increase the number of cards from 6 to 9.

2)  Is a tie possible with 6 cards?  With 7?  8?  9?  10?

3)  How many different ways are there to play the game with 2 cards?  With 3?  4?  5?  6?

4) If both players play very well, who will win – the first player, the second player – or will it end in a tie?  With 1 card?  2 cards?  3?  4?  5?  6?  I don’t know the answer for 9 cards.

Games give you a chance to excel, and if you’re playing in good company you don’t even mind if you lose because you had the enjoyment of the company during the course of the game.

Gary Gygax

Standards for Mathematical Practice

MathPickle puzzle and game designs engage a wide spectrum of student abilities while targeting the following Standards for Mathematical Practice:

MP1 Toughen up!

Students develop grit and resiliency in the face of nasty, thorny problems. It is the most sought after skill for our students.

MP2 Think abstractly!

Students take problems and reformat them mathematically. This is helpful because mathematics lets them use powerful operations like addition.

MP3 Work together!

Students discuss their strategies to collaboratively solve a problem and identify missteps in a failed solution. MathPickle recommends pairing up students for all its puzzles.

MP4 Model reality!

Students create a model that mimics the real world. Discoveries made by manipulating the model often hint at something in the real world.

MP5 Use the right tools!

Students should use the right tools: 0-99 wall charts, graph paper, etc.

MP6 Be precise!

Students learn to communicate using precise terminology. MathPickle encourages students not only to use the precise terms of others, but to invent and rigorously define their own terms.

MP7 Be observant!

Students learn to identify patterns. This is one of the things that the human brain does very well. We sometimes even identify patterns that don't really exist 😉

MP8 Be lazy!?!

Students learn to seek for shortcuts. Why would you want to add the numbers one through a hundred if you can find an easier way to do it?


Please use MathPickle in your classrooms. If you have improvements to make, please contact me. I'll give you credit and kudos 😉 For a free poster of MathPickle's ideas on elementary math education go here.

Gordon Hamilton

(MMath, PhD)