Warm Up Lesson Presentation Lesson Quizzes

Learn to add and subtract fractions.

Additional Example 1A: Adding or Subtracting Fractions with Like Denominators Add. Write the answer in simplest form. 5 8 1 8 + 5 8 1 8 5 + 1 Add the numerators and keep the denominator. + = 8 6 8 3 4 = = Simplify.

Subtract. Write the answer in simplest form. Additional Example 1B: Adding or Subtracting Fractions with Like Denominators Subtract. Write the answer in simplest form. 9 11 4 11 – Subtract the numerators and keep the denominator. 9 11 4 11 9 – 4 – = 11 = 5 11 The answer is in the simplest form.

Check It Out: Example 1A Add. Write the answer in simplest form. 5 6 1 6 + 5 6 1 6 5 + 1 Add the numerators and keep the denominator. + = 6 6 = = 1 Simplify.

Subtract. Write the answer in simplest form. Check It Out: Example 1B Subtract. Write the answer in simplest form. 7 10 4 10 – Subtract the numerators and keep the denominator. 7 10 4 10 7 – 4 – = 10 = 3 10 The answer is in the simplest form.

Additional Example 1: Measurement Application 3 8 5 8 Kevin is 48 inches tall. His brother Keith is 5 inches taller. How tall is Keith ? Add the integers and add the fractions. 3 8 5 8 8 48 + 5 = 53 + 8 = 53 + 1 Rewrite as 1. 54 inches tall. A mixed number is the sum of an integer and a fraction: 3 = 3 + . Helpful Hint 4 5

Add the integers and add the fractions. 72 + 15 87 + Check It Out: Example 1 2 3 Alvin weighs 72 lbs. His baby brother weighs 15 lbs. How much do they weigh together? 1 3 2 3 1 3 3 Add the integers and add the fractions. 72 + 15 = 87 + 3 as 1. = 87 + 1 Rewrite Together they weigh 88 pounds.

Lesson Quizzes Standard Lesson Quiz Lesson Quiz for Student Response Systems

Additional Example 2A: Adding Mixed Numbers Add. Write the answer in simplest form. 2 3 2 3 9 + 12 Add the fractions and then add the integers. 9 2 3 + 12 = 21 + 4 3 Rewrite the improper fraction as a mixed number. Add = 21 + 1 1 3 = 22 1 3 Helpful Hint Add the fractions first in case an improper fraction needs to be rewritten.

Lesson Quiz Add or subtract. Write each answer in simplest form. 5 7 3 7 2 7 3 8 5 8 – + 1 1. 2. 5 12 1 2 11 12 1 3 1 12 1 4 3. + 4. – 7 8 5. You need a nail to go through a -inch door and extend an extra inch. How long should the nail be? 1 4 in. 1 8

Lesson Quiz for Student Response Systems 1. Add. Write your answer in simplest form. + A. 0 C. B. D. 1 4 9 5 9 1 9 1 2

Lesson Quiz for Student Response Systems 2. Subtract. Write your answer in simplest form. – A. C. B. or 1 D. 1 9 11 5 11 4 11 3 11 14 11 3 11 4 11

Lesson Quiz for Student Response Systems 3. Add. Write your answer in simplest form. + A. C. B. D. or 1 3 8 1 3 4 11 17 24 3 11 24 17 7 17

Lesson Quiz for Student Response Systems 4. Subtract. Write your answer in simplest form. – A. C. B. D. or 4 5 12 1 5 4 7 13 60 6 7 60 13 8 13

Lesson Quiz for Student Response Systems 8 9 5. You need pounds of fruits to make a pudding. Sam has pounds of fruits. How much more does he need to make the pudding? A. lb C. lb B. lb D. lb 5 12 17 24 17 36 19 24 19 36