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

2. 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

3. 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.

4. 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,....)

5. Problem- Rounding to nearest whole number
On Monday, Coach Grissom drove 1.4 miles to school. After school he drove 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____

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

7. 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

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

9. 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.

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

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

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

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