1. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc1 ESTIMATING PRODUCTS AND MULTIPLYING FRACTIONS AND WHOLE NUMBERS

2. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc2 ESTIMATING PRODUCTS

3. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc3 Objectives Estimating product using compatible numbers and rounding.

4. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc4 Prerequisite Skill 1.Find the GCF of the following: a) 12, 18GCF = 6 b) 20, 40GCF = 20 c) 13, 23GCF = 1 2.Convert the improper fraction to mixed numbers: a) 55/22=2 ½ b) 38/4 =9 ½ c) 12/5 =2 2/5 3. Round each fraction to 0, ½ or 1: a) 1/10=0 b) 4/7=½ c) 13/14=1

5. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc5 Estimating Products One way to estimate product is to use compatible numbers, which are numbers that are easy to divide mentally. Another method is estimating numbers by rounding to 0, ½ or 1.

6. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc6 Estimate using Compatible Numbers Estimate ¼ x 21. ¼ x 21 means ¼ of 21 Find a number close to 21 that is a multiple of 4 ¼ x 21 ¼ x 20 ¼ x 20 = 520 ÷ 4 = 5 So, ¼ x 21 is about 5 20 and 4 are compatible numbers since 20 ÷ 4 = 5

7. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc7 Example – 2 Estimate 2/3 x 97 Estimate 1/3 x 97 1/3 x 97 1/3 x 96 1/3 x 96 = 32 96 ÷ 3 = 32 If 1/3 of 96 is 32, then 2/3 of 96 = 2 x 32 =64 So, 2/3 of 97 is about 64 96 and 3 are compatible numbers

8. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc8 Try to do by yourself Estimate each product: 3/5 x 27=3/5 x 25 = 15 5/8 x 39=5/8 x 40 = 25 4/7 x 30=4/7 x 28 = 16 5/9 x 20=5/9 x 18 = 10 ¼ x 33= ¼ x 36 = 9

9. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc9 Estimate by rounding to 0, ½ or 1 Estimate 1/3 x 8/9 1/3 x 8/9 = ½ x 1 = 1 1/10 x 6/14 = 0 x ½ = 0 9/16 x 27/50 = ½ x ½ = 1 24/26 x 29/31 = 1 x 1 = 1

10. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc10 Now Your Turn Estimate each product: a)4/5 x 2/9=1 x 0 = 0 b)5/8 x 11/12 =1 x 1 = 1 c)¼ x 9/10=0 x1 =1 d)5/11 x 1/9=½ x 0 = 0 e) 9/10 x ¾ =1 x 1 = 1

11. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc11 Let’s have fun Free Kids Games from theKidzpage.com -- Breakdown Flash GameFree Kids Games from theKidzpage.com -- Breakdown Flash Game

12. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc12 Estimate with Mixed Numbers Round each mixed number to the nearest whole number For example: 11 ¾ x 8 1/7 11 ¾ to 12 and 8 1/7 to 8 11 ¾ x 8 1/7 = 12 x 8 = 96 So, the product is about 96

13. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc13 Your Turn! Estimate each product: 7 2/3 x 5 1/6=8 x 5 = 40 2 9/10 x 11 ¾ =3 x 12 = 36 8 ¼ x 8 6/7=8 x 9 = 72

14. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc14 MULTIPLYING FRACTIONS

15. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc15 Multiply Fractions and Whole Numbers To multiply fraction and a whole number, first write the whole number as a fraction. Then multiply the numerator and denominator. Simplify the fraction.

16. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc16 Multiplying fractions & whole numbers Example 1: ¼ x 13 = ¼ x 13/1 = 1 x 13 4 x 1 = 13/4 = 3¼

17. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc17 Example – 2 ¾ x 24 = ¾ x 24/1 = 3 x 24 4 x 1 = 72/4 = 18

18. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc18 Your Turn Multiply and Simplify: 1.1/8 x 15=7 1/8 2.1/7 x 28 =4 3.3/8 x 2 =¾ 4.4/6 x 12=8 5.1/6 x 37=6 1/6

19. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc19 Let’s solve this puzzle http://www.thekidzpage.com/onlinejigsawp uzzles/jigsaw-puzzles/12-piece- jigsaw/012206hermitcrab.htmlhttp://www.thekidzpage.com/onlinejigsawp uzzles/jigsaw-puzzles/12-piece- jigsaw/012206hermitcrab.html

20. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc20 Word Problems Funky and his froggie friends took 39 minutes to reach Frog School. If they hopped for 2/3 of the time, how many minutes did they spend for hopping? 2/3 x 39=2/3 x 39/1 = 2 x 39 = 78 3 x 1 3 = 26

21. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc21 Now your turn In my class of 48 students, 1/8 study French and 1/6 study Russian and 5/12 of them study English as their language subject. How many students study French, English and Russian? Number of students studying French = 1/8 x 48 = 6 Number of students studying English = 5/12 x 48 = 5 x 4 = 20 Number of students studying Russian = 1/6 x 48 = 8

22. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc22 Assessment Sheet- 1 Estimate: 1.6/11 x 78=42 2.7/13 x 24=14 3.5/9 x 71=40 4.10 2/3 x 1 ¼ =11 x 1 = 11 5.2 ¾ x 7 2/3 =3 x 8 = 24 6.1 3/5 x 1 ¾ =2 x 2 = 4 Estimate by rounding numbers 5/8 x ¾=½ x 1 = ½ 8.4/5 x 1/10=1 x 0 = 0 9.3/5 x 2=½ x 2 =1 10. 3/7 x ¾=½ x 1 = ½

23. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc23 Assessment Sheet – 2 Multiply and simplify: 1.3/8 x 3=1 1/8 2.4/15 x 20=5 1/3 3.5/4 x 8=10 4.4/7 x 21=12 5.9/10 x 23=2 7/10 6.4/5 x 50=40 7.3/5 x 2=1 1/5 8.6/15 x 45=18 9.½ x 15=7 ½ 10.9/81 x 36 = 4

24. CHAPTER 7 Copyright (C) Ed2Net Learning, Inc24 Good Work Do the problems carefully