Students should have an understanding of the inverse relationship between addition and subtraction.
Played in small groups of three students.
Deck of cards with face cards removed
Form small groups of three students. Have each group sit in a small circle facing each other.
Provide each group with a deck of cards (face cards removed) and place the pile in the center of their circle.
Select one player to be the “Announcer”. The other two players will be the “Contestants”. Students will switch roles after each round.
The Announcer deals each contestant one card face down.
When the Announcer announces “Salute”, both Contestants will pick up their card without looking at it and place it on their forehead. Contestants will be able to see their opponent’s card, but they will not know which card they have themselves.
The Announcer will look at both cards and use mental math to add the cards together. Then the Announcer will announce the sum aloud to both Contestants (e.g., If Contestant 1 is holding a four and Contestant 2 is holding an eight, the Announcer will announce a sum of 12).
Once the sum has been announced, the Contestants’ goal is to determine what card they have on their forehead using addition or subtraction (e.g., If the sum is 12, Contestant 1 can see that Contestant 2 has an eight on their forehead, therefore Contestant 1 must be holding a four. 12 − 8 = 4).
Students can use paper and a pencil to record their equations or show their work (optional).
The Announcer will confirm whether the Contestants’ answers are correct. The first contestant to correctly determine which card they are holding will keep both of the contestant’s cards.
Repeat the above steps for five rounds. After five rounds have been played, the player to the right of the Announcer becomes the new Announcer. Players continue to alternate roles every five rounds until they have used all cards in the deck.
The player with the most cards at the end of the game wins.
What strategies do students use to determine their number (e.g., do they use addition or subtraction to determine their number)?
Can students quickly identify math facts when given the sum (e.g., do students quickly recognize doubles facts)?
Play salute using multiplication and division strategies. The Announcer will multiply the Contestants’ cards and announce the product. Each Contestant will have to perform a division equation to determine the card they are holding. (e.g., If Contestant 1 has a four and Contestant 2 has an eight, the Announcer will announce the product 32. Contestant 1 knows that Contestant 2 has an eight, so they must divide 32 ÷ 8 = 4 to determine the card is a four).