1. Place Value ThousandsHundredsTensOnesDecimal Point TenthsHundredths 1247.63  The place value chart below shows 1247.63  The number 1248.63 is one more than 1247.63  The number 1147.63 is one hundred less tan 1247.63  The number 1247.83 is two tenths more than 1247.63

2. Review Where is the decimal place? 34 $5698 508 67.89 HIDDEN DECIMAL

3. Review Arrange each set of numbers from greatest to least! What strategy did you use? A) 1.8, 2.8, 1.9 B) 365.7, 358, 365.9

4. Review – Learn Alberta Place Values http://www.learnalberta.ca/content/memg/index.html?term=Division02/Place_Value/index.html

5. Review – Adding and Subtracting Decimals What do you need to do? 1. Line up the decimals 2. Add zeros into place values that are empty (if you wish) 3. Ex: 12.3 + 2. 4 =12.312.3 + 2.4 + 02.414.7

6. Review – Adding and Subtracting Decimals What do you need to do? 1. Line up the decimals 2. Add zeros into place values that are empty (if you wish) 3. Ex: 187.415 + 34.6 = 187.415 187.415 1. + 34.6 +034.600

7. 2.1 Add and Subtract Decimals Pg 44 Vocabulary: Estimate: to approximate an answer Overestimate : Estimate that is larger than the actual answer Underestimate : Estimate that is smaller than the actual answer

8. Where Does it Fit? Example #1 87.85 + 14.60 + 73.52 = 175.97 Use Front-End Estimation: Notice the leading digits 8,1 and 7 all represent tens! ***Think 80 + 10 + 70 = 160*** Using front-end estimation: 160 is a good estimation

9. Where Does it Fit? Example #1 87.85 + 14.60 + 73.52 = 175.97 Use Relative Size: The leading digits are all in the tens position, so estimate each number to the nearest ten. 87.85 is between 80 and 90, and closer to 90 14.60 is between 10 and 20, and closer to 10 73.52 is between 70 and 80, and closer to 70 ***Think: 90 + 10 + 70 = 170*** Using relative size: 170 is a good estimation

10. Where Does it Fit? Example #1 87.85 + 14.60 + 73.52 = 175.97 Use Compensation: (try to round up - round down) The leading digits are all in the tens position, so estimate each number to the nearest ten. 87.85 is closer to 90 (round up) 14.60 is closer to 10 (round down) 73.52 is closer to 70 (round down) ***Think: 90 + 10 + 70 = 170*** Using compensation: 170 is a good estimation

11. Where Does it Fit? Example #1 87.85 + 14.60 + 73.52 = 175.97 Use Compatible numbers: (5’s, 10’s 50’s 100’s 1000’s) 87.85 is closer to 90 14.60 is closer to 10 73.52 is closer to 70 ***Think: 90 + 10 + 70 = 170*** Using compatible numbers: 170 is a good estimation

12. Try Another One Example #2 4956.2 – 1542.1 = 3414.1 Use Front-End Estimation: Notice the leading digits 4,1 all represent thousands! ***Think 4000 – 1000 = 3000*** Using front-end estimation: 3000 is an OK estimation Could we make a better estimation?

13. Try Another One? Example #2 4956.2 – 1542.1 = 3414.1 Use Relative Size: The leading digits are all in the thousands position, so estimate each number to the nearest thousand. 4956.2 is between 5000 and 4000, and closer to 5000 1542.1 is between 2000 and 1000, and closer to 2000 ***Think: 5000 – 2000 = 3000*** Using relative size: 3000 is a OK estimation

14. Try Another One? Example #2 4956.2 – 1542.1 = 3414.1 Use Compensation: (try to round up - round down) The leading digits are all in the thousands position, so estimate each number to the nearest thousands. 4956.2 is closer to 5000 (round up) 1542.1 is closer to 2000 (round up) ***Think: 5000 – 2000 = 3000*** Using compensation: 3000 is a OK estimation

15. Where Does it Fit? Example #1 4956.2 – 1542.1 = 3414.1 Use Compatible numbers: (5’s, 10’s 50’s 100’s 1000’s) 4956.2 is closer to 5000 1542.1 is closer to 1500 ***Think: 5000 – 1500 = 3500*** Using compatible numbers: 3500 is the BEST estimation

16. Try It On Your Own! Rewrite each question using front-end estimation. Then estimate each answer. A) 45 + 33 + 92 ____ + ____ + ____ = ____ B) $475.12 - $210.38 _________ - ________ = ________ Is your estimate higher or lower than the calculated answer? _____________

17. Try It On Your Own! Use any strategy to estimate the answers. A) 45 + 33 + 92 ____ + ____ + ____ = ____ B) $475.12 - $210.38 ________ - ________ = _______

18. Try It On Your Own! Using estimation, where would you put the decimal point in the answer? A) 631.5 + 902.4 + 217.83 = 175173 ______ + ______+ ______ = _______ B) $475.12 - $210.38= $26474 _______ - _______ = _______

19. Try These On Your Own! For Homework Due Tomorrow! Pg 48. #4, 7, 8ac, 10ac, 14, 20, 21 Extend 22, 24, 25 Page 2.1 worksheet

20. Multiplying Decimal Numbers Problem : Page 52 Ashley and Marshall’s family keep busy travelling across the country by solving sudoku puzzles! During a stop, they look in a convenience store for more puzzles. Marshall finds sudoku books on sale for $1.69. he wants to buy five books and has $9.00. Help him estimate the total cost of the five puzzle books! $1.69 x 5 = ______?

21. Multiplying Decimal Numbers 1. Marshall estimates the total bill as $5.00 a) How do you think Marshall got his estimate? b) Is Marshall’s estimate over or under the total ? How do you know? 2. Ashley estimates the total bill as $10.00 a) How do you think Ashley got her estimate? b) Is Ashley’s estimate over or under the total? How do you know?

22. Sudoku  Sudoku was invented hundreds of years ago, and traded around the world by ancient mathematicians.  Each digit from 1 to 9 must occur in:  Each row  Each column  Each 3 x 3 square. DID YOU KNOW!!! !

23. Multiplying Decimals Use front-end estimation and relative size to estimate: 2.65 x 3.72 Front-End Estimation: Relative Size:

24. Multiplying Decimals Estimate to make sure your answer is reasonable! Multiply 1.54 x 25 What strategy will you use?

25. Multiplying Decimals Use a calculator to solve the equation: Multiply 1.54 x 25 25 x 1 = 25 25 x 2 = 50 HINT: The answer lies between 25 and 50.

26. Multiplying Decimals Using paper and pencil Multiply without decimals add decimals to product Ex: 2.6 x 3.7=26 x37 962

27. Multiplying Decimals Learn Alberta http://www.learnalberta.ca/content/me5l/html/math5.html?goLesson=10 Slides 1-5

28. Practice Makes Perfect Page 57 3, 6ab, 9, 13, 14,17 Extend 20, 21

29. Dividing Decimal Numbers Example 1: A) 15.4 ÷ 3.6 = 4.27778 Front-End Estimation: Think: 15 ÷ 3 = 5 The answer closest to 5 is 4.27778

30. Dividing Decimal Numbers Using a Number Line Ex: 10 ÷ 2 =

31. Use Estimation to Place the Decimal Point. Example #2: Four friends buy 1.36L of pure orange juice and divide it equally. A) Estimate each person’s share. B) Calculate each person’s share.

32. Use Estimation to Place the Decimal Point. Solution: A) To estimate, round 1.36L to a number that is easier to work with. Try 1.2 1.2 ÷ 4 = 0.3 Underestimate Try 1. 1.6 ÷ 4 = 0.4 Overestimate 12 ÷ 4 = 3 So 1.2 ÷ 4 = 0.3 16 ÷ 4 = 4 So 1.6 ÷ 4 = 0.4

33. Dividing Decimals Problem Questions : 1. How many pens do you think you can buy with $6.00 if one pen costs $0.40 Use both front-end estimation and relative size estimation to find your educated guess. 2. How many pens can you purchase! Calculate your answer.

34. Working Together!! Pg 66 #10 A package of 7 fish hooks costs $17.99 How much will one fish hook cost? 1) Estimate 2) Calculate- by hand and with calculator 3) Did you over/under estimate? ANSWER: $17.99 ÷ 7 = $2.57

35. Working Together! Pg 66 #11 Ashley wants to find how many 355 mL cans of juice are in a 2-L bottle. A) Show Ashley how to estimate the answer B) Show Ashley how to calculate the answers

36. Dividing Decimals Learn Alberta http://www.learnalberta.ca/content/me5l/html/math5.html?goLesson=10 Slides 6-10

37. Assignment Page 65 – 67 #4, 8, 12, 13, 14, 17, 19 Extend #21, 22

38. BEDMAS Remember the order by the phrase B - BRACKETS E - EXPONENTS D/M – DIVIDE OR MULTIPLY A/S – ADD OR SUBTRACT

39. The “B” and “E” The “B” stands for items in brackets Do all items in the brackets first The “E” stands for Exponents Do anything that has a exponent (power) 8282 (2 + 3)

40. The “DM” Represents divide and multiply Do which ever one of these comes first in the problem Work these two operations from left to right

41. The “AS” Represents Add and Subtract Do which ever one of these comes first Work left to right You can only work with 2 numbers at a time.

42. 1) 5 + (12 – 3) 5 + 9 14 2) 8 – 3 x 2 + 7 8 - 6 + 7 8 - 6 + 7 2 + 7 2 + 7 9 3) 39 ÷ (9 + 4) 39 ÷ 13 39 ÷ 13 3

43. 4) 10 + 8 ÷ 2 – 6 10 + 4 - 6 14 - 6 8 5) 15 x 10 3 15 x 1,000 15 x 1,000 15 000 15 000 6) 36 ÷ (1 + 2) 2 36 ÷ 3 2 36 ÷ 3 2 36 ÷ 9 36 ÷ 9 4 7) 3 x 10 4 3 x 10 000 3 x 10 000 30 000 30 000

44. 8) (5 – 1) 3 ÷ 4 4 3 ÷ 4 64 ÷ 4 16 9) 14 + 3(7 -2) – 2 x 5 14 + 3 x 5 - 2 5 14 + 3 x 5 - 2 5 14 + 15 - 2 x 5 14 + 15 - 2 x 5 14 + 15 – 10 14 + 15 – 10 29 – 10 29 – 10 19 19

45. Let’s Practice Place the operations shown in square brackets to make each statement true. 9__ 5__5 = 50 (+, x) 15 __ 3 __2 = 24 (x,-)

46. Let’s Practice What are the missing numbers? A) _____ + 5 x 6 = 32 B) _____ - 3.2 ÷ 0.5 = 5

47. Assignment Page 71-73 # 5, 6ab, 7ab, 9ab, 11, 14, 17, 18a, 19 Extend #22, 23, 24