By: J aime Holderbaum

1. By: J�aime Holderbaum

2. Rounding Numbers to the Nearest Ten, Hundred, and Thousand Project Title: Rounding Numbers Audience: This presentation is for third grade students. Instructional Objectives: MAT.IV.1.E2 Investigate and develop an understanding of the base ten place value system Round whole numbers to the nearest thousand

3. What is rounding numbers? You can estimate when you need to know about how many or about how much. Rounding is one way to estimate. http://youtube.com/watch?v=L2lM4agM3xUhttp://youtube.com/watch?v=L2lM4agM3xU

4. Rounding to the Nearest Ten You estimate which ten the number you are rounding is closest to. If you saw a road sign that said Flint was 17 miles away, then you could say that Flint is about 20 miles away. 10 11 12 13 14 15 16 17 18 19 20 17 rounds to 20 Because 17 is closer to 20 than 10

5. Look at these examples. Try to determine what the rule is for rounding to the nearest ten. 12 rounds to 10 24 rounds to 20 33 rounds to 30 51 rounds to 50 80 rounds to 80 91 rounds to 90 43 rounds to 40 64 rounds to 60 Choose the rule: If the number in the ones column is 0, 1, 2, 3, or 4 then round up to the greater ten. If the number in the ones column is 0,1,2,3, or 4, then round down to the lesser ten.

6. Sorry. Look at the numbers in the ones column. Do they cause the number to be rounded to the lesser ten or the greater ten.

7. Yes!! You are correct. When a number has a 0, 1, 2, 3, or 4 in the ones column you round to the lesser ten! For example 83 rounds to 80.

8. Look at these examples. Try to determine what the rule is for rounding to the nearest ten. 9 rounds to 10 17 rounds to 20 25 rounds to 30 48 rounds to 50 76 rounds to 80 88 rounds to 90 36 rounds to 40 Choose the rule: If the number in the ones column is 5, 6, 7, 8, or 9 then round up to the greater ten. If the number in the ones column is 5, 6, 7, 8, or 9 then round down to the lesser ten.

9. Sorry. Look at the numbers in the ones column. Do they cause the number to be rounded to the lesser ten or the greater ten

10. Yes!! You are correct. When a number has a 0, 1, 2, 3, or 4 in the ones column you round to the lesser ten! For example 83 rounds to 80.

11. Think of rounding like a car going over a hill. If you are to round 54 to the nearest ten, then your choices are either round back to 50 or up to 60. You always need to look at the number in the ones column. If the car goes up to 54 and stops, then it will roll back to 50.

12. Here is another example. If you are to round 87 to the nearest ten, then your choices are either round back to 80 or up to 90. If the car goes to 87 and stops, then it will roll to 90.

16. Now it�s your turn to round to the nearest ten! Round 67 70 100 60

22. Next you will learn about rounding to the nearest hundred. When rounding to the nearest hundred, you are finding out which hundred a number is closest to.

23. Rounding to the Nearest Hundred You estimate which hundred the number you are rounding is closest to. If you saw a road sign that said Swartz Creek was 230 miles away, then you could say that Swartz Creek is about 200 miles away. 200 210 220 230 240 250 260 270 280 290 300

24. Look at these examples. Try to determine what the rule is for rounding to the nearest hundred. 241 rounds to 200 532 rounds to 500 333 rounds to 300 710 rounds to 700 912 rounds to 900 829 rounds to 800 101 rounds to 100 427 rounds to 400 Choose the rule: If the number in the tens column is 0, 1, 2, 3, or 4 then round up to the greater hundred. If the number in the tens column is 0,1,2,3, or 4, then round down to the lesser hundred.

25. Sorry. Look at the numbers in the tens column. Do they cause the number to be rounded to the lesser hundred or the greater hundred?

26. Yes!! You are correct. When a number has a 0, 1, 2, 3, or 4 in the tens column you round to the lesser hundred! For example 429 rounds to 400.

27. Look at these examples. Try to determine what the rule is for rounding to the nearest hundred. 563 rounds to 600 179 rounds to 200 499 rounds to 500 381 rounds to 400 262 rounds to 300 958 rounds to 1000 674 rounds to 700 755 rounds to 800 Choose the rule: If the number in the tens column is 5, 6, 7, 8, or 9 then round up to the greater hundred. If the number in the tens column is 5, 6, 7, 8, or 9 then round down to the lesser hundred.

28. Sorry. Look at the numbers in the tens column. Do they cause the number to be rounded to the lesser hundred or the greater hundred?

29. Yes!! You are correct. When a number has a 5, 6, 7, 8, or 9 in the tens column you round to the greater hundred!

30. Remember the example of the car going over the hill.When rounding to the nearest hundred, any number that ends in 49 or less will cause the car to roll back to the lesser hundred and any number that ends in 50 or greater, will cause the car to roll up to the greater hundred.If you round 720 to the nearest ten, then your choices are either round back to 700 or up to 800. If the car goes up to 720 and stops, then it will roll back to 700.

31. Here is another example. If you round 360 to the nearest hundred, then your choices are either round back to 300 or up to 400. If the car goes to 360 and stops, then it will roll to 400.

35. Round to the nearest hundred. Round 581 500 550 600

41. Last you will learn to round to the nearest thousand! When you round to the nearest thousand you are estimating which thousand the number is closest to.

42. Rounding to the Nearest Thousand You estimate which thousand the number you are rounding is closest to. If you saw a road sign that said Posen was 2600 miles away, then you could say that Posen is about 3000 miles away. 2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000

43. Look at these examples. Try to determine what the rule is for rounding to the nearest thousand. 2456 rounds to 2000 5302 rounds to 5000 3289 rounds to 3000 7367 rounds to 7000 8422 rounds to 8000 7056 rounds to 7000 1245 rounds to 1000 9135 rounds to 9000 Choose the rule: If the number in the hundreds column is 0, 1, 2, 3, or 4 then round up to the greater thousand. If the number in the hundreds column is 0,1,2,3, or 4, then round down to the lesser thousand.

44. Sorry. Look at the numbers in the hundreds column. Do they cause the number to be rounded to the lesser thousand or the greater thousand?

45. Yes!! You are correct. When a number has a 0, 1, 2, 3, or 4 in the hundreds column you round to the lesser thousand! For example 8368 rounds to 8000.

46. Look at these examples. Try to determine what the rule is for rounding to the nearest thousand. 4589 rounds to 5000 6900 rounds to 7000 3682 rounds to 4000 2766 rounds to 3000 1805 rounds to 2000 5693 rounds to 6000 8954 rounds to 9000 7725 rounds to 8000 Choose the rule: If the number in the hundreds column is 5, 6, 7, 8, or 9 then round up to the greater thousand. If the number in the hundreds column is 5, 6, 7, 8, or 9 then round down to the lesser thousand.

47. Sorry. Look at the numbers in the hundreds column. Do they cause the number to be rounded to the lesser thousand or the greater thousand?

48. Yes!! You are correct. When a number has a 5, 6, 7, 8, or 9 in the hundreds column you round to the greater thousand!

49. Let�s look at the hill again. If you are to round 6300 to the nearest thousand, then your choices are either round back to 6000 or up to 7000. If the car goes up to 6300 and stops, then it will roll back to 6000.

50. Here is another example. If you are to round 2900 to the nearest thousand, then your choices are either round back to 2000 or up to 3000. If the car goes to 2900 and stops, then it will roll to 3000.

54. Now it�s your turn to round to the nearest thousand! Round 2045 2000 2050 2100

60. http://www.aaamath.com/g41c-round1000.html#section2 http://www.aaamath.com/g41c-round1000.html#section2