Games & Play / Card Games / Game 9

What’s the Secret Number?

Work backward to figure out what two numbers added together will reach the total.


Activity Summary

In this collaborative 2-player game, players work together to figure out the secret number that’s being added to the center card in each round.



  • Take out all face cards and all cards numbered 6 through 10. Aces count as 1.
  • Be sure to shuffle the cards.
  • Put all the remaining cards (1 through 5) in a pile in the center of the table number side down.
  • Model for your child how to play a round before beginning the game.


How a turn begins:

Player 1 takes a card from the center pile and puts it number side up on the table. Player 1 takes a second card and holds it so the other players can’t see it. Player 1 silently adds this secret number to the number on the table. Player 1 tells Player 2, “When I add this number (pointing to the card on the table) to my secret number, the total equals ___. What’s my secret number?” Player 2 must figure out what secret number Player 1 is holding. As an example, if Player 1 is holding the secret number 2, they would say that the total is 7. Player 2 figures out what the missing number is and says, “Is your secret number a 2?” If the answer is not correct, Player 1 says “Try again.”

How a turn ends:

At the end of each turn, Player 1 shows Player 2 the secret number. Players 1 and 2 double check to make sure the answer is correct. Player 1 puts all the cards number side down in the discard pile next to the center pile. Then it is player 2’s turn.

How the game ends:

The players continue to take turns picking cards and figuring out the secret card until time is up or they run out of cards.


Read the Mini Story

  • Make playing even more fun by telling a story about the game: Sneeze likes to figure out secret numbers. Can you help her? In this game, Sneeze will see only one number and we’ll have to help her figure out the other number. Ready? Sneeze and her family say: “Achoo, achoo. My sneeze is through. I’m ready for a card game. How about you?”

Support Learning

  • If your child is finding it hard to figure out the missing number, provide encouragement (“Is there another way you can figure it out?”). Helping your child try to figure out the answer is better for learning than telling them they were wrong.
  • Show your child a way to find the missing number more effectively: “We need 8 and we have 5. Let’s see how many more we need, 5 (hold up one finger), 6 (hold up an additional finger), 7 (hold up an additional finger), 8! How many more fingers did I need to make 8? Let’s count them: 1, 2, 3. Three is the secret number.”
  • If your child is having difficulty with the task, make up a story to go with the numbers. For example, if there is a 5 on the table and you are holding a 2, you could say, “I have 5 cookies. I want 7 cookies. How many more cookies do I need to get 7 cookies?” 
  • Ask your child “How do you know?” This question can be used at any time, whether your child is correct or incorrect. If they are correct, it will help them explain their strategy. If they are incorrect, they can figure this out on their own.
  • Use answers from past turns as hints. For example, suggest, “If we need 2 more to make 7, how many do we need to make 8?”

Adjust the Challenge

Make It Harder

  • Add higher numbers to the deck of cards one at a time until you’re playing with all cards, 1 to 10.

What to Play Next

If your child is still practicing the skills in this game, then continue having fun playing this game! Try the tips to support learning and ways to adjust the challenge. When your child is ready for a new game, play Hidden 10s.

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