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1 3 __ (See answers in margin.) (4, because 3 (3, because 4 (6, 12, 18, 24, 30, 36) What do you do to the denominator? and 6 6 and (You add them.) with a denominator of 12, which number will you with a denominator of 12, which number will you

PDF Pages 1 3 3 4 __ __ Watch for students who add denominators. If it helps these (4, 8, 12, 16, 20, 24) . Have one member of the group draw a diagram of the problem. Have

(Nothing. It stays the same.) In Example 2, what is a common denominator of To rename multiply each part of the fraction by? To rename multiply each part of the fraction by? If you add fractions with the same denominator, what do you do to the numerators? 2 5 __

• • • • facility in naming equivalent fractions. When adding two or more fractions with like denominators, the problem solver simply adds the numerators or the number of fractional parts in each addend. The denominator that shows the number of fractional parts in the whole does not change. When adding fractions that have unlike denominators, the problem solver must first rename the addends using a common denominator. Fraction Fraction addition requires a firm understanding of the meaning of a fraction’s numerator (the number of fractional parts at hand) and denominator (the number of fractional parts in the whole) as well as +

1 2 to find the product of the two denominators. Check Understanding Divide the class into groups of 3 and ask each group to solve the problem __ the other members use the algorithm. The group members then compare their answers to make sure they are the same. If they are not the same, have the group members correct the error. When you are reasonably certain that most of your students understand the algorithm, assign the “Check Your Understanding ” exercises at the bottom of page 21. Error Alert students, tell them to draw a diagram for each problem. This will help them see the denominator as the number of fractional parts in the watch for students who have difficulty finding common denominators. Explain to students that an easy way to find a common denominator of two fractions is circle any numbers that are on both lists. Tell students that the circled numbers are common multiples of 4 and 6. If necessary, have students find common multiples of other number pairs, such as 4 and 10, 6 and 8, and 6 and 9. Using page 21, explain that when adding fractions with different denominators, students will need to find a common multiple of the denominators, or a common denominator. Then, they will rename these fractions using this common denominator. You may want to explain that renaming fractions will be easier if students use the smallest common denominator. Use questions like the following to guide students through the examples: Build Understanding Review the process of finding common multiples. Have students list a few multiples of 4 0 2

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