My 7-year-old daughter keeps beating me at Spot it!

I have an excuse. While playing, I start thinking about the mathematics behind the game rather than the cards in front of me.

The goal of Spot it! is to be the fastest player to spot and call out the matching symbol between two cards. There are 55 cards, each with 8 symbols. Between any two cards there is one, and only one, matching symbol. How did the designers accomplish this? Sue VanHattum explores this question on her blog, Math Mama Writes.

In addition to thinking “How did they do that?” I started thinking about creating a smaller math version of Spot it! What if, rather than symbols, students matched equivalent expressions? A game might consist of 21 cards, each with 5 expressions (e.g., \sqrt {64}, 2^{3}, \dfrac {4} {3}\div \dfrac {1} {6}, \left( -2\right)\left( -4\right), and 8).

I began by creating 7 cards, each with 3 letters. While I was trying to create 13 cards, each with 4 letters, I finally asked “Why am I doing this?” Okay, so the game might be fun for some students, but would it increase their conceptual understanding? Of course not. We’re talkin’ about practice.

I have decided to walk away from creating these types of activities. It won’t be easy. The card stock! The laminator! The paper cutter! I love these things more than a grown man should. I’m quitting. Cold turkey.

But first, check out my latest Tarsia jigsaws…

factoring trinomials tarsia (normal)
factoring trinomials tarsia (larger)
factoring trinomials tarsia (solution)

rational exponents tarsia (normal)
rational exponents tarsia (larger)
rational exponents tarsia (solution)

13 Replies to “My 7-year-old daughter keeps beating me at Spot it!”

  1. I think a really useful activity would be to make this game…so maybe if you REALLY want to play the game, you can give your students some time to make it for themselves.

  2. David, you’re right. There would be value in having students make the game. When I played the game, my first question was “How many possible cards can be created?” – kind of a cool application of combinatorics. If there are 55 different symbols, then there are 55 choose 8, or 1 217 566 350, possible cards. My second question – “How do I design choose/create 55 of 1 217 566 350 possible cards so that there is exactly one match?” – is more interesting. I was hoping the solution to this would also involve combinatorics. If it does, it goes beyond Math 12 (i.e., my understanding). Students’ systematic solutions might lead to something interesting and completely different. (I haven’t returned to Sue’s post – I might revisit this problem at a later date.)

  3. Thanks for your great feedback! You might be interested to know that Blue Orange Games is coming out with a set of limited edition games that will help kids learn the alphabet, numbers and shapes, as well as basic, English, French and Spanish. They’ll be offered at a discounted price for teachers. To stay tuned, find us on Facebook at



  4. Lorraine,

    Thanks for letting me know about this. Any chance you or someone else at Blue Orange can answer why there are 55 not 57 cards? Or maybe the big question – How did they do that?


  5. I am an elementary school teacher and my students love the Spot It. I would like to recreate it for my vocabulary words using data merge in Indesign. However, I need an excel or csv file to work off of.

    Would someone please post an excel file of the answer? That would be very helpful. Thank you, Eliezer

  6. This is amazing! I am a high school math teacher and this will be fantastic for engaging my kids on a wednesday morning! Thank you so much for creating this lesson/activity.

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