1. OBJ: To find the least common multiple of two numbers.

2. Vocabulary Multiple- the product of the number and any nonzero whole number. Common Multiple – a multiple that is shared by two or more numbers. Least Common Multiple – the least of the common multiples of two or more numbers. Least Common Denominator – the least common multiple of the denominators. You can use the LCD to compare and order fractions.

3. Finding the LCM Method 1 List the multiples of each number. Identify the least number that is on both lists. Example – Find the LCM of 16 and 24. Method 2 Find the common factors of the numbers. Multiply all of the factors, using each common factor only once. Example – Find the LCM of 16 and 24.

4. Find the LCM of 1. 20 and 25 2. 6, 8, and 20 3. 15, 30, 50 4. 15x 2, 27x 5. 6m 2, 10m 3 6. 14ab and 21bc 7. 4g 3 h 2 and 15g 2 h 4

5. Least Common Denominator Write the fractions and simplify. Find the LCD of the fractions. Write the equivalent fractions using the LCD. Compare the numerators. Example – Find the LCD and compare the fractions. 5/6, 7/9 5/8, 13/20 7/12, 11/15 5/16, 3/10

6. Examples One brand of hot dogs is sold in packages of 6. One brand of hot dog buns is sold in packages of 8. What is the least number of hot dogs Kimberly can buy and be able to buy an equal number of hot dog buns? Last year a poll of 1200 students found that 300 spoke a first language other than English. This year a poll of 10,000 students found that 4000 students spoke a first language other than English. In which year was the fraction of non-English first language speakers greater?

7. How do you find the LCM of two or more numbers? What is the least common multiple of three numbers that are relatively prime?