The Number Detective[Spying the number]

A Math game using playing cards

A game to immerse children in Math with the essence of Math- there are multiple solutions to a problem!

This game is suitable for 1st graders to 4th graders. Or even for adults who just want to sharpen their thinking and a fruitful pastime activity.

What do you need: A deck of playing cards. Yes! That’s all. You can also use UNO and adapt this game.

Number of players: 2 or more.

How do we play: The steps are quite simple and can be adapted to players

  • Remove the picture cards from the deck. That should leave you with 40 cards of the standard deck.
  • Shuffle them and place them in a grid facing up. Here, the cards are arranged in the grid of 8X5. You can change the grid to suit the place you have or even for variety.
  • Player one gives the lead. For example player one says “I spy numbers that together make 8.”
  • The other player picks up cards that make up 8. E.g. 5 and 3. These cards will be kept in front of the player with cards facing up.
  • The second player makes up the total by picking up another set of numbers E.g. 4 and 4
  • The turns take till no further possibilities can be seen.
  • Players will make separate pile of cards and keep aside with them before the next ‘spying’
  • The player who picks the last possibility now becomes the spy leader and announces ” I spy numbers that…”
  • If a player misses to locate a pair, the next player can be given an extra chance or 5 points- whatever is suitable.
  • There will be gaps, so bring the cards closer after every one ‘spying’.
  • The winner is the player who has maximum number of piled cards with them.
  • You can also assign points (lets say 5) for each possibility. Award player 5 points for each spied number ‘cracked’. Add up the total in that case at the end of the cards to declare the winner.
  • Use the spy statements for all basic Math operations – “numbers that when multiplied…” or “when subtracted..” or “when divided..”. You can use “factors of..” “multiples of..” to level up.
  • You can make it a bit more challenging by specifying colors to be used while the cards are picked up
  • Rack your brains to add complexity.
  • Enjoy the game.
  • Can be played online as well. Just need to decide the screen share and the way in which points are kept.

Benefits of the game: You improve math skills since each player has to come up with a ‘spy’ statement. Players become observant. Develops logical and analytical thinking and creativity to imbibe “every problem has multiple solutions”.

Photo credit: Shweta Nagar

6 thoughts on “The Number Detective[Spying the number]

Add yours

  1. Middle school students could consider the red cards to be negative and the black cards to be positive, too.

    I just have one question: Are all the cards returned to the grid before the next student spies a new sum, difference, product, or quotient?


    1. Nice suggestion for negative and positive! That could make it more complex and interesting!

      I had envisioned that cards will be mixed, shuffled and laid out into a grid once all possibilities are over. Since the number of cards get reduced, it will become more complex and hence players will have to be on their toes. If there are more players, we can add 2 pack of cards. That also leads to a closure of one “round” of turns.

      In case, you try out returning the cards and re-laying the grid, do let me know how it went! 🙂


    1. I am glad that you liked this. I have tried a variation for higher concepts like sets, sequences etc using this game. DO let me know if you find these variations useful. And do let me know if you make any variations! Thanks!!


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