Divisibility Rules are quite interesting and when you add in a game with cards then kids learn them even faster. The first two cards turned over in the game determine a two-digit number that will be the base for this game. There’s always a slim chance that the number you turn over will be prime, in which case there’s really no game to be had. Most combinations will provide an adequate number of factors. Each player turns over a card when it’s his or her turn. If the card turned over represents a factor of the target number then it’s kept. If it’s not, then it’s discarded.
As the players go through the deck taking turns, it’s the luck of the draw whether the card turned over will be useful or not. In the meantime it’s a fun way for students to learn the divisibility rules or to get a refresher if they were introduced to them before. Notice that the instructions say to remove 7, 8, and the face cards from the deck, but for more challenge you could definitely add the 7 and 8 cards back in. Even though they don’t have easy-to-apply divisibility rules, the students can still check with mental math or a piece of scratch paper to see if these numbers are factors.
For a very challenging game, you can step up to three-digit numbers when your students are ready. Also, as an adaptation, throw the Jacks back into the deck. If a player turns over a Jack, he or she will skip a turn. And as we know with the luck of the draw, that might make or break the game.
Common Core Mathematical Standard
4.OA Gain familiarity with factors and multiples.
6.NS Compute fluently with multi-digit numbers and find common factors and multiples.
