1. ALGEBRA READINESS LESSON 5-4 Warm Up

2. ALGEBRA READINESS LESSON 5-4 Warm Up

3. ALGEBRA READINESS “Dividing Rational Numbers” (5-4) What are “reciprocals”? How do you find the reciprocal of a number? Reciprocals: two numbers whose product is 1 – The reciprocal of is, since = 1. To find the reciprocal of a number, simply switch the numerator and denominator around. In the case of a whole number, make it a fraction by putting it over 1 first (so, the reciprocal of a whole number will always be 1 over the number) Example: What is the reciprocal of 9? 9 =  Make the whole number into a fraction by putting it over 1. =  Turn the fraction over so that the numerator and denominator are switched 9 = = 1  Check using rule of reciprocals (a number times I ts reciprocal equals 1) abab baba abab baba 9191 9191 1919 1919 911911 191191

4. ALGEBRA READINESS Write the reciprocal of each number. 4949 a. b. 5 Since = 1, the 4949 9494 reciprocal of is. 4949 9494 Since 5 = 1, the reciprocal of 5 is. 1515 1515 Dividing Rational Numbers LESSON 5-4 Additional Examples

5. ALGEBRA READINESS “Dividing Rational Numbers” (5-4) How do you divide by a fraction? How do you model the division of fractions? To divide by a fraction, multiply by its reciprocal. Rule:  = =, where b, c, and d do not equal 0. Example: What is the  ?  =  To divide by a fraction, multiply by its reciprocal =  Multiply the numerators and denominators separately. = = 4  The fraction bar means divide, so divide the numebrator into the denominator to simplify.  =, so there are 4 one-eighth parts in one- half. abab cdcd abab dcdc adbcadbc 1212 1818 1212 1818 8181 1212 1212 8181 1 8 2 1 8282 1212 4848

6. ALGEBRA READINESS One bow takes yards of ribbon. How many bows could you make from a roll of ribbon that is 12 yards long? 3434 1212 You need to find how many -yard pieces there are in 12 yards. 3434 1212 Divide 12 by. 3434 1212 Multiply by, the reciprocal of. 25 2 4343 = 3434 4343 25 2 3434 1212 3434 Write 12 as an improper fraction. 1212 12 ÷ = ÷ Dividing Rational Numbers LESSON 5-4 Additional Examples

7. ALGEBRA READINESS (continued) Divide numerator and denominator by their GCD, 2. 25 2 4343 = 1 2 Multiply. Write the fraction as a mixed number. = = 16 50 3 2323 Because you cannot make of a bow, you can make 16 bows. 2323 Dividing Rational Numbers LESSON 5-4 Additional Examples

8. ALGEBRA READINESS Write the reciprocal of each number. 1. 2. 11 Find each quotient. 3. 4. 5. Megan has 3.5 quarts of punch. One serving is quart. How many servings does she have? 1414 1 11 14 (–1 ) ÷ (1.5) 7878 4747 – – 1616 – 3434 ÷ ( ) 7474 – 2929 1414 – 1 Dividing Rational Numbers LESSON 5-4 Lesson Quiz