1. Math Review 1. 10 2 5 - 7 3 4 2. 3x - 7 = 533. Simplify 44 32 4. Estimate 5.42 + 6.59 to the nearest tenth. 5. Which of the following statement is true about this graph? a. These students spend more time at school than doing anything else. b. These students spend equal amounts of time on homework and watching t.v. c. These students spend equal amounts of time on homework and doing chores. d. These students spend less time playing outside than doing chores. Answer Key 1. 2 13/20 2. x=20 3. 1 3/8 4. 5.4 + 6.6 = 12.0 5. c Answer Key 1. 2 13/20 2. x=20 3. 1 3/8 4. 5.4 + 6.6 = 12.0 5. c

2. Estimation Objective: I can make estimates using whole numbers, decimals, and fractions. 3.87 ≈ 4 7 ≈ 8 2 3

3. Essential Questions 1. What is estimation? How should you use it to determine the reasonableness of your answer? 2. What is estimation? Why should you use it to determine the reasonableness of your answer? 3. What is estimation? When do I use it? 4. What is rounding? Why is it important to estimation?

4. Adding & Subtracting Estimation You can estimate an answer before you calculate, to make sure your answer is reasonable. The symbol ≈ means “is approximately equal to.”

5. Check It Out...

6. Estimating Decimals 1.Find the place value you want (the "rounding digit") and look at the digit just to the right of it. 2.If that digit is less than 5, do not change the rounding digit but drop digits to the right of the decimal. 3.If that digit is greater than or equal to five, add one to the rounding digit and drop digits to the right of the decimal.

7. Let’s Try It! Estimate the following to the given place value: 74.29 to the nearest tenth 50.009 to the nearest hundredth 69.45898 to the nearest thousandth 203.978 to the nearest hundredth 74.3 50.01 69.459 203.98

8. Now Try These! Estimate to the nearest hundredths place...then solve. 84.034 - 32.982 345.0285 + 272.9762 581.236 - 87.2346 84.03 - 32.98 =51. 05 345.03 + 272.98 =72. 05 581.24 - 87.23 =494.01

9. Estimating with Fractions Sometimes it is better to round a fraction to the nearest half in order to estimate an addition or subtraction problem…

10. For Example 0 ½ 1 3 5 Draw a number line Divide the line up into equal portions of your denominator’s value Decide whether it is closer to a whole or a half 3 5 1 5 2 5 It is closer to ½

11. Let’s Try a Couple... 0 ½ 1 6 7 2 7 1 7 3 7 4 7 5 7 6 7 It is closer to 1 Draw a number line Divide the line up into equal portions of your denominator’s value Decide whether it is closer to a whole or a half

12. Estimating Mixed Numbers Is 5 closer to 5, 5 ½, or 6? 3 8 5 5½ 6 Draw a number line Divide the line up into equal portions of your denominator’s value Decide whether it is closer to a whole or a half 3 8 5 2 8 5 1 8 5

13. Round these mixed numbers to the nearest half… 2 4 9 12 5959 5 8 11 6 9 13 2 3 2½ 12 13 12½ 5 6 5½ 6 7 6½

14. Round Each Fraction to Add and Subtract 7 1616 + 1 3737 4 2323 + 9 4545 - 6 2929 2 5858 - 7 + 1 ½ + 5 = 13½ 10 - 6 - 3 = 1 Remem ber... Estimat e first!

15. Now Let’s Estimate! Jack has some 24 pieces of licorice rope. He gives 2 and 3/4 pieces to Jill, 6 and 5/9 to Jim, and 9 and 9/11 to June. How much does he have left for himself? Remem ber... Estimat e first! 3 +6 ½ +10 = 19½ 24 - 19 ½ = 4½

16. Now You Try It! Jennifer ordered two pizzas to share with her friends. She gives Jeff 3/8 of the pizza and her girlfriends eat 7/8 of the pizza. How much pizza will she have left for herself? 2 - ½ - 1½ = ½

17. Closure On a sticky note describe the process of estimating with decimals or fractions.

18. Independent Practice Estimation 1. Estimate to the nearest tenth.. 23.49 + 34.78 5 7979 + 3 1717 8 3535 += 2. Estimate to the nearest hundredth.. 54.938 + 160.781 3. Estimate to the nearest dollar.. $59.10 - $23.91 4. 9 4 7 6 4 5 Is closer to 9, 9 ½, or 10? 5. Is closer to 6, 6 ½, or 7? 6. 7. 9 2323 - 1 4747 3 5858 -= 8. Amanda has some 16 candy bars. She gives 4 and 3/4 bars to William, 3 and 3/9 to Orrin, and 2 and 1/11 to Athena. How much does she have left? Answer Key 1. 23.5 + 34.8 = 58.3 2. 54.94 + 160.78 = 215.72 3. $59 + $24 = $83 4. 9 1/2 5. 7 6. 6 + 3 + 8 1/2 = 171/2 7. 10 - 1 1/2 - 3 1/2 = 5 8. 16 - 5 - 3 - 2 = 7 Answer Key 1. 23.5 + 34.8 = 58.3 2. 54.94 + 160.78 = 215.72 3. $59 + $24 = $83 4. 9 1/2 5. 7 6. 6 + 3 + 8 1/2 = 171/2 7. 10 - 1 1/2 - 3 1/2 = 5 8. 16 - 5 - 3 - 2 = 7