Copyright © ed2netlearning.inc 1 Dividing Fractions and Whole numbers

Copyright ©Ed2NetLearning.Inc 2 Previous Knowledge Multiply: 1.½ x ½ x 20 =5 2.2/3 x 2/5=4/15 3.3/20 x 1 ¼ =3/ /3 x 2 ¼ =7 ½ 5.5 x 1 2/3=8 1/3

Copyright ©Ed2NetLearning.Inc 3 Objective Identify and understand the term reciprocal To understand division of fractions and whole problems To do problems based on division

Copyright ©Ed2NetLearning.Inc 4 Reciprocal of a fraction Any two numbers whose product is 1 are called reciprocals. To find the reciprocal of a particular fraction, inter change the numerator and denominator. For example reciprocal of 2 = 3 3 2

Copyright ©Ed2NetLearning.Inc 5 Practice Problems Find the reciprocal of the following: 1.7/2=2/7 2.4/5=5/4 3.2/3=3/2 4.5/6=6/5 5.7/12=12/7 6.5/33=33/5 7.1/8=8/1=8

Copyright ©Ed2NetLearning.Inc 6 Dividing a whole number by a fraction To divide a whole number by a fraction, » step 1: Write the whole number as a fraction. » step 2: Find the reciprocal of the divisor or second fraction. » step 3: Multiply the dividend and reciprocal of the divisor. » step 4: Write the resultant answer in lowest terms.

Copyright ©Ed2NetLearning.Inc 7 Example – 1 Find 3 ÷ ¼ 3 ÷ ¼ = 3 ÷ ¼ 1 Reciprocal of ¼ = 4/1 3 ÷ ¼ = 3 x 4 = 12 = Write the whole number as fraction

Copyright ©Ed2NetLearning.Inc 8 Example – 2 Find 4 ÷ 2/3 4 ÷ 2/3=4/1 ÷ 2/3 =4/1 x 3/2 =12/2 =6.

Copyright ©Ed2NetLearning.Inc 9 Practice Problems Divide: 1.3 ÷ ½=6 2.9 ÷ 1/6= ÷ 7/5= ÷ ¾=42 2/3 5.4 ÷ 1/8=32

Copyright ©Ed2NetLearning.Inc 10 Dividing a fraction by a whole number To divide a fraction by a whole number: Step 1: Write the whole number as a fraction. Step 2: Find the reciprocal of the divisor. Step 3: Multiply the dividend and the reciprocal of the divisor. Step 4: Simplify.

Copyright ©Ed2NetLearning.Inc 11 Example - 1 Find ¾ ÷ 9 ¾ ÷ 9=¾ ÷ 9 1 =¾ x 1 9 = 3 x 1 4 x 9 =3 =

Copyright ©Ed2NetLearning.Inc 12 Practice Problems Divide 1. 5/7 ÷ 2=5/ /3 ÷ 13=1/ /12 ÷ 4=1/ /7 ÷ 5=4/ /6 ÷ 5=1/6 6. 1/8 ÷ 4 =1/32

Copyright ©Ed2NetLearning.Inc 13 Word Problems Miss. Kate and her friend Joe made 4 pizzas. They decided that ½ pizza will be given to each person. How many of ½ pizzas were there? 4 ÷ ½ = 4 x 2 = 8 pieces

Copyright ©Ed2NetLearning.Inc 14 Word Problem ¾ bottles of orange juice has to be poured into 6 glasses. If an equal amount of juice has to be put into each glass, how much of the juice will each glass hold? ¾ ÷ 6=¾ x 1/6 =1/8 Each glass will hold 1/8 of the juice in the bottle.

Copyright ©Ed2NetLearning.Inc 15 Now Your Turn 1.Mrs. Anne bought 50 pound bags of dog food to feed the dogs. If each dog gets 5/6 pound of food, how many dogs can she feed with one bag? Answer: 50 ÷ 5/6 = 50 x 6/5 = 10 x 6 = 60 dogs

Copyright ©Ed2NetLearning.Inc 16 Another Question 2. Lucy wants to divide a sweet into five equal parts. The sweet is 5/8 feet long. How long will each sweet be? Answer: 5/8 ÷ 5=5/8 x 1/5 =1/8 ft long.

Copyright ©Ed2NetLearning.Inc 17 Review Any two numbers whose product is 1 are called reciprocals. To divide a whole number by a fraction, multiply the reciprocal o the divisor with the dividend. To divide a fraction by a whole number, multiply the reciprocal of the whole number and multiply it with the fraction.

Copyright ©Ed2NetLearning.Inc 18 Assessment Divide the following: 1. 1/3 ÷ 2 =1/6 2. ½ ÷ 4=1/8 3. 3/5 ÷ 2=3/ /3 ÷ 5=2/ ÷ 1/5= ÷ 1/3= ÷ 5/6 =9 3/ ÷ 3/10=3 1/ ÷ ¾ = /7 ÷ 3=3/7

Copyright ©Ed2NetLearning.Inc 19 Great Job!!