Adding and Subtracting with Like Denominators 4-8 Warm Up Problem of the Day Lesson Presentation Course 1

4-8 Adding and Subtracting with Like Denominators Warm Up Course 1 4-8 Adding and Subtracting with Like Denominators Warm Up Write each mixed number as an improper fraction. 1. 6 2. 2 3. 3 4. 8 5. 9 6. 4 1 3 __ 19 3 __ 1 5 __ 11 5 __ 2 7 __ 23 7 __ 1 2 __ 17 2 __ 4 5 __ 49 5 __ 8 11 __ 52 11 __

4-8 Adding and Subtracting with Like Denominators Problem of the Day Course 1 4-8 Adding and Subtracting with Like Denominators Problem of the Day Marge has six coins that total $1.15. She cannot make change for $1.00, a half-dollar, a quarter, a dime, or a nickel. What coins does she have? half dollar, quarter, 4 dimes

4-8 Learn to add and subtract fractions with like denominators. Course 1 4-8 Adding and Subtracting with Like Denominators Learn to add and subtract fractions with like denominators.

Additional Example 1: Application Course 1 4-8 Adding and Subtracting with Like Denominators Additional Example 1: Application 1 4 __ Snow was falling at a rate of inch per hour. How much snow fell after two hours? Write your answer in simplest form. 1 4 __ 1 4 __ + 1 4 __ 1 4 __ 2 4 __ Add the numerators. Keep the same denominator + = 1 2 __ = Write your answer in simplest terms. + = 1 2 __ After 2 hours inch of snow fell

4-8 Adding and Subtracting with Like Denominators Try This: Example 1 Course 1 4-8 Adding and Subtracting with Like Denominators Try This: Example 1 1 8 __ Rain was falling at a rate of inch per hour. How much rain fell after two hours? Write your answer in simplest form. 1 8 __ 1 8 __ + 1 8 __ 1 8 __ 2 8 __ Add the numerators. Keep the same denominator. + = 1 4 __ = Write your answer in simplest terms. + = 1 8 __ After 2 hours inch of rain fell.

Additional Example 2A: Subtracting Like Fractions and Mixed Numbers Course 1 4-8 Adding and Subtracting with Like Denominators Additional Example 2A: Subtracting Like Fractions and Mixed Numbers Subtract. Write the answer in simplest form. A. 1 – 3 5 __ To get a common denominator, rewrite 1 as a fraction with a denominator of 5. 5 __ 3 5 __ 2 5 __ – = Subtract the numerators. Keep the same denominator. ― =

Additional Example 2B: Subtracting Like Fractions and Mixed Numbers Course 1 4-8 Adding and Subtracting with Like Denominators Additional Example 2B: Subtracting Like Fractions and Mixed Numbers Subtract. Write the answer in simplest form. B. 5 – 2 5 12 __ 1 12 __ 5 12 __ 1 12 __ 5 – 2 Subtract the fractions. 4 12 __ 3 Then subtract the whole numbers. 1 3 __ 3 Write your answer in simplest form. - =

4-8 Adding and Subtracting with Like Denominators Try This: Example 2A Course 1 4-8 Adding and Subtracting with Like Denominators Try This: Example 2A Subtract. Write the answer in simplest form. A. 1 – 2 6 __ To get a common denominator, rewrite 1 as a fraction with a denominator of 6. 6 __ 2 6 __ 4 6 __ – = Subtract the numerators. Keep the same denominator. – =

4-8 Adding and Subtracting with Like Denominators Try This: Example 2B Course 1 4-8 Adding and Subtracting with Like Denominators Try This: Example 2B Subtract. Write the answer in simplest form. B. 4 – 2 7 12 __ 4 12 __ 7 12 __ 4 12 __ 4 – 2 Subtract the fractions. 3 12 __ 2 Then subtract the whole numbers. 1 4 __ 2 Write your answer in simplest form. - =

Additional Example 3A: Evaluating Expressions with Fractions Course 1 4-8 Adding and Subtracting with Like Denominators Additional Example 3A: Evaluating Expressions with Fractions 2 9 __ Evaluate the expression for x = . Write each answer in simplest form. 5 9 __ A. – x 5 9 __ – x Write the expression. 2 9 __ 5 9 __ 2 9 __ 3 9 __ Substitute for x and subtract the numerators. Keep the same denominator. – = 1 3 __ = Write your answer in simplest form.

Additional Example 3B: Evaluating Expressions with Fractions Course 1 4-8 Adding and Subtracting with Like Denominators Additional Example 3B: Evaluating Expressions with Fractions 2 9 __ Evaluate the expression for x = . Write each answer in simplest form. 4 9 __ B. x + 2 4 9 __ x + 2 Write the expression. 2 9 __ 2 9 __ 4 9 __ 6 9 __ Substitute for x. Add the fractions. Then add the whole numbers. + 2 = 2 2 3 __ 8 3 __ Write your answer in simplest form. = 2 , or

Additional Example 3C: Evaluating Expressions with Fractions Course 1 4-8 Adding and Subtracting with Like Denominators Additional Example 3C: Evaluating Expressions with Fractions 2 9 __ Evaluate the expression for x = . Write each answer in simplest form. 8 9 __ C. x + 8 9 __ x + Write the expression. 2 9 __ 2 9 __ 8 9 __ 10 9 __ 1 9 __ Substitute for x and subtract the numerators. Keep the same denominator. + = , or 1

4-8 Adding and Subtracting with Like Denominators Try This: Example 3A Course 1 4-8 Adding and Subtracting with Like Denominators Try This: Example 3A Evaluate the expression for x = . Write each answer in simplest form. 2 6 __ 4 6 __ A. – x 4 6 __ – x Write the expression. 2 6 __ 4 6 __ 2 6 __ 2 6 __ – = Substitute for x and subtract the numerators. Keep the same denominator. 1 3 __ = Write your answer in simplest form.

4-8 Adding and Subtracting with Like Denominators Try This: Example 3B Course 1 4-8 Adding and Subtracting with Like Denominators Try This: Example 3B Evaluate the expression for x = . Write each answer in simplest form. 2 6 __ 1 6 __ B. x + 3 1 6 __ x + 3 Write the expression. 2 6 __ 2 6 __ 1 6 __ 3 6 __ Substitute for x and subtract the numerators. Keep the same denominator. + 3 = 3 1 2 __ Write your answer in simplest form. = 3

4-8 Adding and Subtracting with Like Denominators Try This: Example 3C Course 1 4-8 Adding and Subtracting with Like Denominators Try This: Example 3C Evaluate the expression for x = . Write each answer in simplest form. 2 6 __ 5 6 __ C. x + 5 6 __ x + Write the expression. 2 6 __ 2 6 __ 5 6 __ 7 6 __ 1 6 __ Substitute for x and subtract the numerators. Keep the same denominator. + = , or 1

4-8 Adding and Subtracting with Like Denominators Lesson Quiz Course 1 4-8 Adding and Subtracting with Like Denominators Lesson Quiz Add or subtract. Write each answer in simplest form. 1. 1 – 2. 1 – 4. Evaluate – x for x = . 9 11 __ 2 11 __ 8 9 __ 1 9 __ 3 10 __ 1 10 __ 2 5 __ 3. 2 + 4 6 16 21 ___ 6 21 __ 10 21 __ 3 4 __ 5. Weston walks of a mile every day. How far will he have walked in 4 days? 3 miles