2. 1.1 Estimate, round, & manipulate very large…numbers. Number Sense Sense

3. 1.5 Identify & represent on a number line…positive integers. Number Sense SenseFifth Grade Grade

4. 2.3 Use a variety of methods, such as numbers…and models to explain mathematical reasoning. MathematicalReasoningFifth Grade Grade

5. Objectives To To be able to round numbers to the nearest ten be able to round numbers to the nearest hundred be able to round numbers to the nearest thousand

6. Vocabulary Round Round – to replace an exact number by another that is close to it in value and easier to use. For example, 52, rounded to the nearest ten is 50.

7. Use rounding When the question asks you to estimate. When the question asks “about how many”…? When an exact answer isn’t possible. When an answer is difficult to obtain.

8. Memorize this Poem Find the place value. Look right next door. 4 or less just ignore. 5 or more, add 1 more. Sweep the numbers to the right off the floor. Change them to zeros forevermore.

9. Round this number to the nearest ten. Find the place value. 4 7 Circle the number in the ten’s place.

10. Round this number to the nearest ten. Look right next door. 4 7 Draw an arrow to the right of the number.

11. Round this number to the nearest ten. 4 or less, just ignore. 4 7 7 is larger than 4 so go to the next line of the poem.

12. Round this number to the nearest ten. 5 or more, add 1 more. 4 7 Add 1 to the 4. +1

13. Round this number to the nearest ten. Sweep the numbers to the right off the floor. 5 75 7 After adding 1 to the 4, remove all the numbers to the right of the ten’s place.

14. Round this number to the nearest ten. Change them to zeros forevermore. 5 7 Put a zero in its place. 0

15. The Answer 4 7 rounded to the nearest ten’s place is 5 0 40 5047 Note 47 is closer to 50 on the number line.

16. Round this number to the nearest hundred. Find the place value. 9 8 6 Circle the number in the hundred’s place.

17. Round this number to the nearest hundred. Look right next door. 9 8 6 Draw an arrow to the right of the hundred’s place.

18. Round this number to the nearest hundred. 4 or less, just ignore. 9 8 6 8 is larger than 4 so go to the next line of the poem.

19. Round this number to the nearest hundred. 5 or more, add 1 more. 9 8 6 Add 1 to the 9. +1

20. Round this number to the nearest hundred. Sweep the numbers to the right off the floor. 1, 0 8 6 After adding 1 to the 9, remove the numbers to the right of the hundred’s place.

21. Round this number to the nearest hundred. Change them to zeros forevermore. 1, 0 8 6 Put zeros in their place. 0

22. The Answer 986 rounded to the nearest hundred’s place is 1, 0 0 0 900 986 Note 986 is closer to 1,000 on the number line.

23. Round this number to the nearest ten thousand. Find the place value. 3 6 8,9 7 1 Circle the number in the ten thousand’s place.

24. Round this number to the nearest ten thousand. Look right next door. 3 6 8,9 7 1 Draw an arrow to the right of the number.

25. Round this number to the nearest ten thousand. 4 or less, just ignore. 3 6 8,9 7 1 8 is larger than 4 so go to the next line of the poem.

26. Round this number to the nearest ten thousand. 5 or more, add 1 more. 3 6 8,9 7 1 Add 1 to the ten thousand’s place value. +1

27. Round this number to the nearest ten thousand. Sweep the numbers to the right off the floor. 3 7 8,9 7 1 After adding 1 to the 6, remove all the numbers to the right of the ten thousand’s place.

28. Round this number to the nearest ten thousand. Change them to zeros forevermore. 3 7 8,9 7 1 Put zeros in their place. 0,0 0 0

29. The Answer 368,971 rounded to the nearest ten thousand is 3 7 0,0 0 0 360,000 370,000368,971 Note 368,971 is closer to 370,000 on the number line.

30. Round this number to the nearest thousand. Find the place value. 3 5, 3 2 7 Circle the number in the thousand’s place.

31. Round this number to the nearest thousand. Look right next door. 3 5, 3 2 7 Draw an arrow to the right of the number.

32. Round this number to the nearest thousand. 4 or less, just ignore. 3 5, 3 2 7 Since 3 is less than 4 we do not change the 5.

33. Round this number to the nearest thousand. Sweep the numbers to the right off the floor. 3 5, 3 2 7 Remove all the numbers to the right of the thousand’s place.

34. Round this number to the nearest thousand. Change them to zeros forevermore. 3 5, 3 2 7 Put zeros in their place. 0 0 0

35. Answer 35,327 rounded to the nearest thousand is 3 5, 0 0 0 36,00035,327 Note 35,327 is closer to 35,000 on the number line.

36. Round this number to the nearest dollar. Find the place value. $ 5. 8 7 Circle the number where the dollars are.

37. Round this number to the nearest dollar. Look right next door. $ 5. 8 7 Draw an arrow to the right of the circled number.

38. Round this number to the nearest dollar. 4 or less, just ignore. $ 5. 8 7 8 is greater than 4 so go to the next line of the poem.

39. Round this number to the nearest dollar. 5 or more, add 1 more. $ 5. 8 7 Since 8 is greater than 5 add 1 to the dollar place value. +1

40. Round this number to the nearest dollar. Sweep the numbers to the right off the floor. $ 6. 8 7 After changing the 5 to a 6, remove the numbers to the right of the dollar.

41. Round this number to the nearest dollar. Change them to zeros forevermore. $ 6. 8 7 Put zeros in their place. 0

42. The Answer $5.87 rounded to the nearest dollar is $ 6. 0 0 $5.00$6.00$5.87 Note $5.87 is closer to $6.00 on the number line.

43. Round this number to the nearest tenth place. Find the place value. 4. 8 7 1 Circle the number in the tenth’s place.

44. Round this number to the nearest tenth place. Look right next door. 4. 8 7 1 Draw an arrow to the right of the circled number.

45. Round this number to the nearest tenth place. 4 or less just ignore. 4. 8 7 1 8 is greater than 4 so go to the next line of the poem.

46. Round this number to the nearest tenth place. 5 or more, add 1 more. 4. 8 7 1 Since 7 is greater than 5, add 1 to the tenth’s place. +1

47. Round this number to the nearest tenth place. Sweep the numbers to the right off the floor. 4. 9 7 1 Remove the numbers to the right of the tenth’s place value.

48. Round this number to the nearest tenth place. Change them to zeros forevermore. 4. 9 7 1 With decimals you don’t have to add zeros to the right.

49. The Answer 4.871 rounded to the nearest tenth place is 4. 9 4.84.94.871 Note 4.871 is closer to 4.9 on the number line.

50. Here’s Another Strategy The Clothesline Approach

51. Step 1 – Read the problem carefully. Round this number to the nearest thousand. 7,790

52. Step 2 – Circle the place value you are rounding to Round this number to the nearest thousand. 7,790

53. Step 2 – Write down the thousand thousand on either side of this number Round this number to the nearest thousand. 7,790 7,000 8,000

54. Step 3 – Put the smallest number on the left pole and the largest on the right. Round this number to the nearest thousand. 7,790 7,000 8,000 7,0008,000

55. Step 4 – Think where your number would go between these poles. Round this number to the nearest thousand. 7,790 7,0008,000 Now think! 7,500 would go right in the middle. 7,500

56. Step 5 – Hang your number where you think it should go. Round this number to the nearest thousand. 7,790 7,0008,000 7,500 7,790

57. Step 6 – The pole you are closest to is your answer. Round this number to the nearest thousand. 7,790 7,0008,000 7,500 7,790

58. The Answer 7,790 rounded to the nearest thousand is 8,000 7,000 8,0007,790 Note 7,790 is closer to 8,000 on the number line.

59. Round these numbers to the nearest ten. 1 3 9 4 5 2 8 2 9 7 1 4 0 5 0 2 8 0 1 0 0

60. Round these numbers to the nearest hundred. 2, 1 3 9 1 9, 7 4 5 2 8 2 3, 1 9 7 2, 1 0 0 1 9, 7 0 0 3 0 0 3, 2 0 0

61. Round these numbers to the nearest thousand. 2, 8 3 9 1 9, 4 4 5 8, 9 8 2 4 3,1 9 7 3, 0 0 0 1 9, 0 0 0 9, 0 0 0 4 3, 0 0 0

62. Credits Clipart from “Microsoft Clip Gallery” located on the Internet at http://cgl.microsoft.com/http://cgl.microsoft.com/ clipgallerylive/default.asp Clipart from ClickArt 125,000 Deluxe Image Pak, T/Maker Co., Broderbund Software, Inc.