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LCM. Lowest Common Multiple. Multiple. A multiple of a number is the product of that number and a whole number 2, 4, and 6 are multiples of 2 3, 6, and 9 are multiples of 3. Jamie plays on his school’s curling team and on his curling club’s junior team. If he
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LCM Lowest Common Multiple
Multiple • A multiple of a number is the product of that number and a whole number • 2, 4, and 6 are multiples of 2 • 3, 6, and 9 are multiples of 3
Jamie plays on his school’s curling team and on his curling club’s junior team. If he practices every fifth day of the month with the school team, and every third day with his club, on which days of the month will he have to practice with both teams?
Every 5th day school, every 3rd day club • Why do you think the number you found is called the least common multiple (LCM) of 3 and 5?
Finding the LCM Example: What is the least common multiple of 8 and 12? Method 1: List the multiples. The multiples of 8 are The multiples of 12 are The least common multiple of 8 and 12 is
Method 2: Use Prime Factorization (Factor Trees) 8 12 8 = 2 x 2 x 2 12 = 2 x 2 x 3
8 = 2 x 2 x 2 12 = 2 x 2 x 3 • Select the common factors: 2 x 2 • Select the remaining factors: 2 x 3 • Find the product of these factors: 2 x 2 x2 x 3
Example A group of students buys flowers to decorate the gym for graduation. The flower stall sells roses in bunches of 6 and carnations on bunches of 4. What is the smallest number of flowers they can buy to have the same number of each kind?
Practice What is the LCM of the following numbers? • 6 and 12 b) 7 and 4 c) 24 and 35 d) 36, 25 e) 3, 5, and 10
f) A school cafeteria serves fish every 4th school day and spaghetti every sixth school day. Both fish and spaghetti were served on Monday. On which day of the week will they both be served again?
Classwork Pages 37 - 38 #1 – 4, 11, 12, 15, 17, and 18