An answer that is close to the exact answer. Estimation An answer that is close to the exact answer.

Objective In this lesson you will: Estimate problems involving addition, subtraction, multiplication, and division Describe front-end estimation, compatible numbers, rounding up or down to the nearest specified place value, and compensation Tek 5.3A

Words to Know To approximate is to estimate or to come close to. Compatible numbers are numbers that are easy to compute mentally. Compensation an estimation strategy in which numbers are rounded and then mentally adjusted. Digits are the symbols 0,1,2,3,4,5,6,7,8, and 9 used to write numbers. To estimate is to use a strategy that gives you an answer that is close to the exact answer.

Words to Know cont. Front-end estimation is an estimation strategy that uses the front-end digit of a number. Place value is the value of a digit determined by its position in a number. To be reasonable is to be logical or sensible. Whole numbers are the set of counting numbers and zero (0, 1,2,3,4,....)

Problem- Rounding to nearest whole number On Monday, Coach Grissom drove 1.4 miles to school. After school he drove 2.87 miles to the park, 4.9 miles to the grocery store, and 7.12 miles back home. Round each driving distance to the nearest mile to estimate the number of miles Coach Grissom drove on Monday. 1.4 miles→ ___1____ 2.87 miles→ ___3____ 4.9 miles→ ___5____ 7.12 miles→ ___7____ +____________________ Estimated Total Miles = _______16 miles____

Video Watch the video to show you how to estimate by rounding.

Problem: Front-end estimation The chart below shows the numbers of fans who attend the first 3 Rocket games of the season. Use front-end estimation for the estimate of total attendance for the first 3 games. 37,569→ 40,000 42,179→ 40,000 38,461→ 40,000 +____________________ =120,000 fans Game Number of fans 1 37,569 2 42,179 3 38,461

Video Watch video on front-end estimation. Front-end estimation

Problem: Compatible Numbers Jason raked 25 ½ bags of leaves in 6 ⅙ hours. About how many bags of leaves did Jackson rake each hour? Equation: 25 ½ ➗ 6 ⅙ (24 is compatible to 6 therefore easier to divide mentally) 24 ➗ 6 = 4 bags an hour.

Video: COmpatible Number estimation Watch the video on how to use compatible number estimation. Compatible Number Estimation

Problem: Compensation Estimation Adjust estimates to draw closer to an exact calculation. Problem: 496.2 + 308.5 First round the numbers: 496 + 309 Then compensate by increasing one number and decreasing the other number so as to make the computation easier: 500 + 305= 805 The estimate is 805

Video: Compensation estimation Watch the video on how to use the strategy of compensation estimation. Compensation strategy

Show what you Know Click here to practice what you have learned.