The least common multiple, or LCM, of two natural numbers is the smallest number that is a multiple of both numbers. METHOD 1 Section 4.1

Method 2: To find the LCM of a set of numbers using prime factorizations. a) Find the prime factorization of each number. b) Create a product, using each prime factor the greatest number of times that it occurs in any one factorization. Use a FACTOR TREE! Section 4.1

Homework: Problems 9, 11, 19, 21, 29, 33, 37, 39, 41, 45. Copy the problem first. Determine the answer using methods 1 or 2 and shown in the lecture slides. If you can find the LCM another way, GREAT!, but you must still show some work or justification. Section 4.1

Steps to follow: To add when denominators are different: a) Find the least common multiple of the denominators. That number is the least common denominator, LCD. b) Convert each fraction to the LCD. c) Add the numerators, keeping the same denominator. d) Simplify, if possible. Section 4.1

Alyse bought 1/3 lb of orange pekoe tea and 1/2 lb of English cinnamon tea. How many pounds of tea did she buy? Use the 4 step process to solve. Homework: Problems 19, 33, 35. Copy the problem first. Show all of your work in a top down manner. Problems 37, 39, 41, 43, 45, 47, 49 Solve using the 4 step process. Make sure you show all of your work when solving the equations. Section 4.1