They can make only three changes. The first student tries to remember. Students have three cards each. If the winner can supply the correct answer, they take the card from the loser. The aim is to get the most cards and not lose any.
Students have three cards each.
The loser has to select a card, but shows only the back of the card to the winner. If the winner guesses correctly, they take the card. Students then change partners. Every student has three cards. The winner has to guess if it is or not.