Copyright © 2012, 2009, 2005, 2002 Pearson Education, Inc. Chapter 3 Decimals

Copyright © 2012, 2009, 2005, 2002 Pearson Education, Inc. Estimating and Solving Applied Problems Using Decimals 3.7

Copyright © 2012, 2009, 2005, 2002 Pearson Education, Inc. Estimating with Decimals Example: Estimate 238, , , ,905  200, ,000 = 700,000 Example: Estimate 68,976  ,976   70,000  = 63,000 Example: Estimate ÷ ÷ 0.55  30 ÷ 0.60 = 50

Copyright © 2012, 2009, 2005, 2002 Pearson Education, Inc. Problem Solving Steps 1.Understand the problem. a)Read the problem carefully. b)Draw a picture if this is helpful. c)Fill in the Mathematics Blueprint so that you have the facts and a method of proceeding in this situation. 2.Solve and state the answer. a)Perform the calculations. b)State the answer, including the unit of measure. 3.Check. a)Estimate the answer. b)Compare the exact answer with the estimate to see if your answer is reasonable.

Copyright © 2012, 2009, 2005, 2002 Pearson Education, Inc. Mathematics Blueprint Mathematics Blueprint for Problem Solving Key Points to Remember How Do I Proceed? What Am I Asked to Do? Gather the Facts The Mathematical Blueprint is simply a sheet of paper with four columns. Each column tells you something to do.

Copyright © 2012, 2009, 2005, 2002 Pearson Education, Inc. Move the decimal point over two places before dividing. Mathematics Blueprint Example: Kelsey is making holiday cookies, which she will give as gifts to her friends and co-workers. She has made 34.5 pounds of cookies, which need to be divided up into equal packages containing 0.75 pound of cookies. How many packages can Kelsey make? Mathematics Blueprint for Problem Solving Key Points to Remember How Do I Proceed? What Am I Asked to Do? Gather the Facts There are 34.5 lbs of cookies and each package is 0.75 lb. Divide 34.5 by Find the number of packages Kelsey can make. Example continues.

Copyright © 2012, 2009, 2005, 2002 Pearson Education, Inc. Mathematics Blueprint Kelsey is making holiday cookies, which she will give as gifts to her friends and co-workers. She has made 34.5 pounds of cookies, which need to be divided up into equal packages containing 0.75 pound of cookies. How many packages can Kelsey make?  Kelsey can make 46 packages.

Copyright © 2012, 2009, 2005, 2002 Pearson Education, Inc. Multiplication comes before addition. Mathematics Blueprint Example: David bought apples and pears at the grocery store for a fruit salad. At the checkout counter, the apples weighed 2.7 pounds and the pears weighed 1.8 pounds. If the apples cost $1.29 per pound and the pears cost $1.49 per pound, how much did David spend on fruit? (Round your answer to the nearest cent.) Mathematics Blueprint for Problem Solving Key Points to Remember How Do I Proceed? What Am I Asked to Do? Gather the Facts 2.7 lbs of apples costing $1.29/lb.; 1.8 lbs of pears costing $1.49/lb. Apples: multiply 2.7 by 1.29; Pears: multiply 1.8 by 1.49; Add the two products. Find the total cost David spent on the fruit. Example continues.

Copyright © 2012, 2009, 2005, 2002 Pearson Education, Inc. Mathematics Blueprint David bought apples and pears at the grocery store for a fruit salad. At the checkout counter, the apples weighed 2.7 pounds and the pears weighed 1.8 pounds. If the apples cost $1.29 per pound and the pears cost $1.49 per pound, how much did David spend on fruit? (Round your answer to the nearest cent.) David spent $6.17 on the fruit. Apples: Pears :