CECmath.56 TITLE: "24" Game AUTHOR: Elinor Crecelius, Wyoming Girls School; Sheridan, Wyoming GRADE LEVEL: 5-12 OVERVIEW: Here is a game designed to review basic facts and the order of operations in a fun, problem-solving situation. I use it at the beginning of the period to warm-up and focus on math. OBJECTIVE: Students will use four digits obtained from rolling four dice to create a mathematical expression equal to 24. PURPOSE: Basic facts are important to learn, but boring to teach. This game has appealed to all of my students and has stimulated them to use what they do know and master what they don't. RESOURCES/MATERIALS: Four dice, paper, pencils, and calculators if desired. ACTIVITIES AND PROCEDURES: The first four students to class each get a die to roll and call out the number. I record the four numbers on the board. The students are then on their own to come up with a way to reach 24 using any or all of the four operations. For example, if 6,5,6, and 4, were rolled, one solution would be: 4 x 6 / (6 - 5) = 24. When a student has found a way, she writes it on the board as a mathematical expression using the most concise way to communicate her answer. When one way is found and agreed to be correct, many are ready to quit looking. I challenge them to find as many ways as possible to obtain 24 using the given numbers. No answer counts unless it is written with the appropriate symbology. Although which operation used is not restricted, each number must be used only once. TYING IT ALL TOGETHER: This activity appeals to all levels. If appropriate, the use of exponents can be added. for instance, if the numbers 6, 4, 2, and 1 are rolled, one solution would be, 1 to a power of 3(6x4). As well as forcing a recall of basic facts, order of operations becomes a point of interest, and the idea of math symbols being used to communicate one student's thoughts to the rest of the class is stimulating.