Numbers and Operations Use groups of 2. Materials: Index cards, spinners

y not x?

Copy onto cards the questions shown below, one question per card. Shuffle the cards and place them face down in a pile. Label equal sections of one spinner "4," "15," "25," "30," "50," "75," "80," "125." Label equal sections of a second spinner "2," "12," "20," "25," "40," "60," "90," "120." Decide which spinner you will use to replace the variable x and which spinner you will use to replace the variable y in the percent questions. (Partners must choose different spinners.)

One partner selects the top card from the pile. Each partner then spins a spinner. Partners replace x and y in the question on the card with the numbers on the spinners and then write an equation in P = R · B form. The partner with the greater solution wins the round. Play several rounds, taking turns selecting a card.