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Adding & Subtracting Fractions Teacher Notes: Use this presentation to teach the steps for adding and subtracting fractions with unlike denominators. It is assumed that students have a thorough understanding of the process for making equivalent fractions. CLICK HERE to view a demonstration with opportunities for students to practice making equivalent fractions.

Step 1: Find a common denominator to add these fractions. +

+ Step 1: Find a common denominator to add these fractions. Count by 2's 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 Count by 7's 7, 14, 21, 28, 35…

Step 3: Add the numerators x 7 7 Step 2: Make equivalent fractions. = X 7 x 2 6 Step 3: Add the numerators = + 7 + 6 = 13 x 2 13 Step 4: Simplify

+ Step 1: Find a common denominator to add these fractions. Count by 7's 7, 14, 21, 28, 35, 42, 49, 56, 63 Count by 5's 5, 10, 15, 20, 25, 30, 35, 40, 45

Step 3: Add the numerators x 5 15 Step 2: Make equivalent fractions. = X 5 x 7 7 Step 3: Add the numerators + = x 7 15 + 7 = 22 22 Step 4: Simplify

+ Step 1: Find a common denominator to add these fractions. Count by 7's 7, 14, 21, 28, 35, 42, 49, 56, 63 Count by 8's 8, 16, 24, 32, 40, 48, 56, 64, 72

Step 3: Add the numerators 32 x 8 Step 2: Make equivalent fractions. = x 8 21 x 7 Step 3: Add the numerators + = 32 + 21 = 53 x 7 53 Step 4: Simplify

Step 1: Find a common denominator to add these fractions. - Count by 5's 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 Count by 11's 11, 22, 33, 44, 55, 66, 77…

Step 3: Add the numerators 15 Step 2: Make equivalent fractions. x 5 = x 5 11 x 11 Step 3: Add the numerators = 15 - 11 = 4 - x 11 4 Step 4: Simplify

Try These A D E B F C

Answers On Next Slide Each click on the next slide reveals an answer. Check your papers. If you discover an incorrect answer, be able to explain your mistake.

Try These 10 9 17 27 A D 41 28 13 12 B E 19 20 26 21 C F