90 likes | 193 Views
EXAMPLE 1. Adding Fractions. 3. 3 + 4. 4. +. =. Add the numerators. 5. 5. 5. 7. Simplify the numerator. =. 5. 2. Rewrite the improper fraction as a mixed number. 1. =. 5. EXAMPLE 2. Subtracting Fractions. 7. 7 − 3. 3. −. =. Subtract the numerators. 10. 10. 10. 4.
E N D
EXAMPLE 1 Adding Fractions 3 3 + 4 4 + = Add the numerators. 5 5 5 7 Simplify the numerator. = 5 2 Rewrite the improper fraction as a mixed number. 1 = 5
EXAMPLE 2 Subtracting Fractions 7 7 −3 3 − = Subtract the numerators. 10 10 10 4 = Simplify the numerator. 10 2 = Simplify the fraction. 5
5 9 1 5 3 6 7 1 1. 2. 3. 4. + + + + 10 9 7 8 10 8 7 9 8 3 = = 9 4 4 1 1 1 = = 5 7 for Example 1 and 2 GUIDED PRACTICE Find the sum or difference. Simplify if possible.
5 8 2 1 8. 5. − − 9 6 9 6 2 1 3 2 = = = = 7 5 6. 7 3 6 3 − 12 12 6 3 7. − 7 7 for Example 1 and 2 GUIDED PRACTICE Find the sum or difference. Simplify if possible.
EXAMPLE 3 Using a Verbal Model RECIPES 5 You and your mom are baking. The recipe uses cup of raisins. You have only cup of raisins. How many more cups do you need? 8 3 8
− Amount you have Amount you need Amount for recipe = Substitute amounts you know. 5 3 − = 8 8 2 = Subtract the fractions. 8 1 = Simplify. 4 1 ANSWER You need cup of raisins. 4 EXAMPLE 3 Using a Verbal Model SOLUTION
EXAMPLE 4 Standardized Test Practice
Length of the Igls track Length of the Lillehammer track Difference in their lengths = + 19 6 = + 25 25 25 , = or1 25 19 6 ANSWER You need to add and . The correct answer is B. 25 25 EXAMPLE 4 Standardized Test Practice SOLUTION
1 You need cup of raisins. 2 − Amount you have Amount you need Amount for recipe = for Example 3 and 4 GUIDED PRACTICE 7 What If? In Example 3, suppose the recipe uses cup of raisins. How many more cups of raisins do you need? Write a model to help you find the answer. Then find the answer. 9. 8 ANSWER