Submit by Email Period: Name: --.... ~r ~ Focus on Ohio Academic Content Standards Lesson 6 Estimate Products and Quotients 1H, 11, 6e, 60: G6.1.13: Print Form Use and analyze the steps in standard algorithms for computing with decimals; Use avariety of strategies to estimate, compute, solve and explain solutions to problems involving decimals; Use more than one strategy to solve a problem; Recognize whether an estimate or exact solution is appropriate for a given problem situationc Estimate reasonable solutions to problem situations involving decimalsc When you estimate, you find an answer that is close to the exact answer. One way to estimate a product is to round each factor to the greatest place. Then multiply the rounded factors. One way to estimate a quotient is to use compatible numbers. Compatible numbers are numbers that are close to the actual numbers but are easier to divide. I Wesley works 7.5 hours a day. About how many hours does he work in a month with 22 workdays? i Guided Itstruction c\........ /\.. Round the factors. Find the product of the rounded factors. :1 Step 2 Round each factor to its greatest place. 7.5 rounds to _ 22 rounds to _ 8x20= Find the product of the rounded factors. _ About how many hours does he work in a month with 22 workdays? Gail's car used 16.2 gallons of gas to go 443.7 miles. About how many miles did the car travel per gallon of gas? Use compatible numbers to estimate the quotient. Step :1 Think: 16.2 is close to 15. What number is close to 443.7 and divisible by 15? c _ Find the quotient of the compatible numbers. 450 -; About how many miles did the car travel per gallon of gas? 18 Mathematics· Level F Copying is illegal. Measuring Up® to the Ohio Academic Content Standards E~tima:e pr:u~;~ and Quotients II!ImII .PPIY the . Ohio Use rounding to estimate each product. Show the numbers you used. ~tandards '-."'-\.. 1. 86.4 x 32 4. 826 x 14.2 7. 43.081 x 556 x 215 3. 55.33 x 29.54 7,653 x 2.4 6. 1,186 x 94.2 63.31 x 9.09 9. 0.46 x 0.32 2. 673 5. 8. Change the divisor and the dividend to compatible numbers. Then use the compatible numbers to estimate the quotient. 10. 1,741 -;- 57.2 11. 23.78 -;- 3.9 12. 81.4 -;- 19.36 13. 5,789 -;- 105.3 14. 35.26 -;- 8.3 15. 467.6 -;- 38 16. 2,792 -;- 74.1 17. 937.2 -;- 17.8 18. 64,975 -;- 77.8 Short Answer Solve each problem. 19. Maury worked 24 days during the month of April. He drove 73.5 miles to work and back each workday. Maury estimated that he commuted about 1,400 miles during the month. Is his estimate less than or greater than his exact commute? Explain how you found your answer. 20. Alex worked 38.75 hours and earned $348.45. His friend Dave worked 22.75 hours and earned $166.31. About how many more dollars per hour did Alex earn than Dave? Describe one situation in which it might be appropriate to estimate this difference. Peoples Education Copying is illegal. Chapter 1 • Operations with Decimals 19 IIICII Estimate P~Oducts and Quoti,e. nts I Ohio AChievement !Practice """-,.,-,,\.. Directions: Read each question. Then circle the letter for the correct answer. /\ .... 1. Charlize worked 1.3 hours one day and 3.5 hours the next day. She earned a total of $28.50. About how much did she earn per hour? ~1~.'(The expression 5L10 -:- 0.9 can be used l/~ ""i, to estimate which of the following expressions? A. 523.3 -:- 0.86 A. $3.00 B. B. $6.00 5L12.3 -:- 0.58 C. 538.07 -:- 0.089 C. $7.00 D. 59L1.081 -:- 0.93 D. $8.00 5. Leo used these compatible numbers to estimate a quotient. When would you need to find an exact answer ra-~her than an es-'-imate? A. checking the reasonableness of an answer 600 -:- 30 = 20 Which division problem could Leo have found an estimate for? B. A. 515.7 -:- 11. 1 B. determining how much money each member of a team must contribute to pay for a coach's gift C. figuring about how far a car can 586.8 -:- 29.5 travel on a full tank of gas C. 668 -:- Ll7 D. predicting how much money will be raised through a bake sale D. 690 -:- 73 3, Ella wrote 68.LI x 19.37 = 1,32L1.908. Which multiplication sentence could she use to check the reasonableness of her answer? A. 70 x 30 B. 20 /\ ,,:)j6.·~:7The machines in a bakery produce ,/y,/"'\ 8 dozen donuts every 2.5 minutes. About how many donuts do the machines produce every hour? 2,100 A. 500 70 x 20 = 1,LlOO B. 1,000 = C. LlO x 30 = 1,200 C. 2,000 D. 50 x 20 = 1,000 D. 3,000 Mathematics • Level F Copying is illegal. Measuring Up® to the Ohio Academic Content Standards