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ESTIMATION. Three Types of Estimation Measurement Estimation Quantity Estimation Computational Estimation If I can drive 326 miles on 15 gallons of gasoline what is my approximate mpg? Is 10 dollars enough to buy 5 drinks that cost $2.19 each?.
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ESTIMATION Three Types of Estimation Measurement Estimation Quantity Estimation Computational Estimation If I can drive 326 miles on 15 gallons of gasoline what is my approximate mpg? Is 10 dollars enough to buy 5 drinks that cost $2.19 each?
Determine a number that is the approximation of a computation. Not a guess, involves some form of reasoning. Sometimes knowing if the result is more or less than a number is sufficient. A Computational Estimate
Multi-Digit Numbers Can be built upon or taken apart in a wide variety of ways. Use easier-to-handle parts of numbers to create estimates. Computation can then be done mentally.
Multi-Digit Numbers Substitute “nice” numbers for hard ones Computation can then be done mentally.
Computational Estimation Use a variety of strategies developed over time Find Real Examples of Estimation Accept a Range of Estimates Focus on Flexible Methods NOT Answers
Understanding Computational Estimation Use the Language of Estimation “About” “Close” “Just about” “A little more than” “A little less than” “Between””
Understanding Computational Estimation Estimating Without Estimates Over or Under? 37+75 Over or Under 100 712-458 Over or under 300 319/45 Over or under 6
Understanding Computational Estimation Estimating Without Estimates High or Low 736 x 18 750 x 10 730 x 15 700 x 20 750 x 20
Computational Estimation Strategies Three methods for Computational Estimation Front End Rounding Compatible (nice/friendly) Numbers In all three--make an initial estimate and then adjust if need be.
Front End Methods 487 + 31 + 710 400+0+700=1100 Adjust to 1200 421/59 400/60=less than 7 Adjust to 7
Rounding Methods $48.17+$1.89+$24.95 $50+$0+$20=70 Adjust to $72 $4.17 x 6 $4 x 6 = $24 Adjust $25
Compatible Numbers 41+29+63+17+65+85 41+63=about100 29+65=about 100 17+85=about 100 300-adjust to a bit more than 300
Compatible Numbers 371/21 400/20=20 Adjust to a few less than 20 69-27 67-27=40 Adjust to a bit more than 40
Estimating with Fractions, Decimals, and Percents Represent Most Real-World Estimations Connect to Computational Skill Development