Everyone at school loves the new collection cards! The cards are from a "Pirates" set. You can collect cards with pirates, parrots, pirate ships, and treasure maps. The rarest cards are the treasure and captain cards.
Simon has almost all the cards, but he is missing the treasure card. It’s very rare, just like the captain card, but Simon already has two captain cards. Kris also collects cards. She has two treasure cards and wants a captain card.
Kris asks Simon to swap cards with her. Kris will give a treasure card for a captain card.
Do you think Simon will swap cards with Kris?
Simon says yes and Kris tells him that she will bring the cards to school the following day. Max also wants a treasure card and doesn’t have one. Max is determined to get one and wants to trade with Kris. But Max knows Kris already promised Simon the treasure card.
Should Max offer Kris a swap, knowing that Kris has already made a promise with Simon? Is this fair?
Max asks Kris to trade two cards for one treasure card.
Kris now has to choose:
She can keep her promise to Simon and
trade only one card for the treasure
card.
She can trade with Max and get one
extra cards.