Numbers and Operations Number of players: 2 Materials: Index cards, spinner

After the Factors

Label equal sections of a spinner "72," "90," "144," "168," "420," "450." Then each partner makes a set of cards containing the prime numbers shown below. (The numbers in parentheses tell how many cards each partner should make for that number.) Shuffle the cards and place them face down in a pile. Each partner takes five cards from the pile.

One partner spins the spinner. Each partner then determines whether he or she is holding cards showing the prime factors of the number on the spinner. If yes, remove these cards from your hand and replace them with cards from the pile. Award yourself 1 point. If no, you may replace some or all of your cards before the next spin. Continue in the same way until one partner has 5 points. (Shuffle and reuse cards that have been discarded.)