What’s My Number?
Choose a secret number.
You may choose to record each guess or play the game without any visual clues.
Extensions:
Choose a secret number within a wider range (1 to 500, 1 to 1000). Then give one clue about your secret number (ends with zero; sum of the digits is ten; etc.). Ask students to investigate the possible numbers and play the game as before.
Play the game using a fraction or a decimal as the secret number.
From Math Solutions: Developing Number Sense Rusty Bresser and Caren Holtzman
- Say the range of numbers your number falls within (1 to 10, 50-100, 1 to 100, etc)
- Have someone guess the number; if their guess is incorrect, announce whether your number is greater than or less than the number guessed.
- Continue until someone guesses your secret number.
You may choose to record each guess or play the game without any visual clues.
Extensions:
Choose a secret number within a wider range (1 to 500, 1 to 1000). Then give one clue about your secret number (ends with zero; sum of the digits is ten; etc.). Ask students to investigate the possible numbers and play the game as before.
Play the game using a fraction or a decimal as the secret number.
From Math Solutions: Developing Number Sense Rusty Bresser and Caren Holtzman
TWENTY-FIVE
This game is good with just about any number of players, but five or fewer makes it move faster.
You need a deck with all the face cards removed.
The objective: to get exactly to 25!
The dealer deals out all the cards face down. Play begins clockwise from the dealer.
- The next person adds his/her top card to the center of the table and says its value.
- The next person adds his/her top card to the center and says the center's value.
- Play continues from one player to the next.
- If a player's card takes the center's value over 25, then the next cards played are subtracted from the center's value until the center's value is once again below 25.
- If players run out of cards, the dealer picks up all the center cards, shuffles them, and deals them again. Play continues normally.
- When a player's card gets the center's value to exactly 25, the game is won and that person becomes the new dealer.
*To make this game more challenging, change the target number to 50 and allow multiplication and division to be used in addition to addition and subtraction.