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3-2 Estimating Decimal Products and Quotients. 1. Estimate the product. How do I estimate the product?. Round to the nearest one 7.65 • 3.2 Estimate 4.72 • 1.8 17.02 • 3.78. 2. Check calculations. How to check calculations…
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1. Estimate the product • How do I estimate the product? • Round to the nearest one • 7.65 • 3.2 • Estimate • 4.72 • 1.8 • 17.02 • 3.78
2. Check calculations • How to check calculations… • Arlene bought 6 yd of fabric to make a quilt. The fabric cost $6.75/yard. The sales clerk charged Arlene $45.90 before tax. Did the clerk make a mistake? • Round to nearest dollar • 6.75 ≈ 7 • Multiply by how many yards she bought
You buy 8 rolls of film. Each roll costs $4.79. Estimate the cost of the film before tax.
3. Estimate the quotient • How do I estimate the quotient? • Compatible numbers – numbers that are easy to divide mentally • Round denominator, then round numerator • A bowling ball has a mass of 5.61 kg. Each bowling pin has a mass of 1.57 kg. How many bowling pins are about equal to the bowling ball in mass? Estimate 5.61 ÷ 1.57 • 5.61 ≈ 6 • 1.57 ≈ 2 • 6 ÷ 2 = 3
38 . 9 ÷ 1.79 • 11.95 ÷ 2.1
3-2 Puzzle Activity Homework: 3-2 Guided Problem Solving pg in WB