2. New Vocabulary VocabularyDefinitionUsing symbols reciprocalFor any nonzero number x, the reciprocal is The number 0 has no reciprocal; The reciprocal of a fraction is the fraction 1x1x abab baba USING RECIPROCALS

4. Reciprocals can help you divide by fractions. Two numbers are reciprocals or multiplicative inverses if their product is 1. USING RECIPROCALS

5. Example: Finding Reciprocals Find the reciprocal. 1 9 __ 1 9 = 1 Think: of what number is 1? 1 9 __ 1 9 1 9 9 = 1 of is 1. 1 9 __ 9 1 The reciprocal of is 9. 1 9 __ USING RECIPROCALS

6. Example: Finding Reciprocals Find the reciprocal. 2 3 __ 2 3 = 1 Think: of what number is 1? 2 3 __ 3 2 2 3 = = 1 6 6 __ of is 1. 2 3 __ 3 2 The reciprocal of is. 2 3 __ 3 2 USING RECIPROCALS

7. 1 5 __ 16 5 __ = 1 Write 3 as. 1 5 __ 5 16 __ 16 5 __ = = 1 80 __ of is 1. 16 5 __ 5 16 __ The reciprocal of is. 16 5 __ 5 16 __ 16 5 __ Example: Finding Reciprocals Find the reciprocal. 3 USING RECIPROCALS

8. Check It Out! Find each reciprocal. 1 8 __ 4 4 1 8 = 33 8 __ ; 8 33 __ USING RECIPROCALS

9. Check It Out! Find each reciprocal. 5 5 = 5 1 __ ; 1 5 USING RECIPROCALS

10. Check It Out! Find each reciprocal. 1 4 __ 2 2 1 4 = 9 4 ; 4 9 USING RECIPROCALS

11. 1. Identify the reciprocal of. A. –15 C. B. D. 15 Student Response Systems USING RECIPROCALS

12. 2. Identify the reciprocal of. A. 15 C. B. 7 D. Student Response Systems USING RECIPROCALS