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Grade 5 Lesson 2.7 Estimating products Objective: To provide experiences with making and using magnitude estimates for products of multidigit numbers, including decimals.
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Math Message In your Math ISN, use the numbers 10, 6, 9, 8 & 5 to make expressions that are equivalent names for 1, 10, and 100. Use addition, subtraction, multiplication, and division, or exponents. Try to use all 5 numbers.
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Magnitude Estimates A magnitude estimate is a VERY ROUGH estimate that allows you to determine whether your solution to a problem is reasonable. It answers questions such as is the solution going to be in the tens? Hundreds? Thousands? Is the result of 14 * 17 going to be in the tens? Hundreds? Or thousands?
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How do I make a magnitude estimate? 1. Round both factors to the nearest multiple of 10. 2. Find the product of the rounded numbers. For example, to estimate 14 * 17, round 14 to 10 and 17 to 20. Multiply 10 and 20 to get 200. 14 * 17 is in the hundreds.
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Workbook Page Please complete page 47 in your workbook. 2.7 Magnitude estimates for products. Do this as independent work. Look at problem 6. You can use magnitude estimates with decimals too. You could.. Round 4.5 to 5 and.6 to 1 then multiply 5 * 1 (solution is in the ones!
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Partner Activity In your math workbooks, perform the spinner experiment with a partner. You can find it on page 48. You will need a pencil and a paper clip (obtain one from your teacher) How are you going to divide up your circle if it needs to be divided into 3 parts? You need to give it a 1/3 chance of landing on red. A ½ chance of landing on blue And a 1/6 chance of landing on green.
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To figure this out, you will need to make equivalent fractions… 1 6 2 = 12 1 4 3 = 12 1 = 2 6 12 Suppose you spin the spinner 36 times. About how many times might it land on a color other than blue? About how many times might it land on a red or blue?
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Homework: Complete Study link 2.7 Magnitude Estimates Homework: Complete Study link 2.7 Magnitude Estimates Enrichment: Using Multiplication Patterns Page 66A Apply your understanding of patterns in the number of zeros in a product when multiplying by powers of 10. Enrichment: Using Multiplication Patterns Page 66A Apply your understanding of patterns in the number of zeros in a product when multiplying by powers of 10.
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