How to play
Students find your secret number between 1 and 100 using no more than 7 yes or no questions. It teaches systematic, organised reasoning, since halving the options each time always works.
- Tell the class you are thinking of a number between 1 and 100.
- Students have no more than 7 yes or no questions to find it.
- As soon as a student asks 'Is it ___?', the game is over, right or wrong.
- Encourage questions that eliminate half the numbers, such as 'Is it between 1 and 50?' or 'Is it odd?'
- Keep a running record on the board of the numbers left.
- With two left, like 51 and 53, a question such as 'Does it end in a 1?' settles it.