1. Rounding numbers to any thousand place value
Lesson 8
Rounding numbers to any thousand place value

2. The goal for this lesson is…
By the end of this lesson you will be able to round a number to any place value by using a vertical number line.

3. Let’s try a problem
This time we are going to round 72,744 to the nearest ten thousand.
How many ten thousands are in 72,744?

4. Problem # 1
There are 7 ten thousands in 72,744.
70,000

5. Problem # 1
What would be ten thousand more?
70,000

6. Problem # 1
80,000
Ten thousand more would be 80,000.
70,000

7. Problem # 1 What is halfway between these numbers? (midpoint) 80,000
70,000

8. Problem # 1
80,000
Did you get 7,500?
75,000
70,000

9. Problem # 1 Where would you put 72,744 on your number line? 80,000
75,000
70,000

10. Problem # 1 So would we round it to 70,000 or 80,000? 80,000 75,000
72,774
70,000

11. Problem # 1
80,000
We would round it to 70,000.
75,000
72,774
70,000

12. Let’s try another one…
This time we are going to round the number 549,085 to the nearest hundred thousand.

13. Problem # 2
How many hundred thousands are in 549,085?

14. Problem # 2
There are 5 hundred thousands in 549,085.
500,000

15. Problem # 2
What would one more hundred thousand be?
500,000

16. Problem # 2
That’s right! ,000
600,000
500,000

17. Problem # 2 What is halfway between these numbers? (midpoint) 600,000
500,000

18. Problem # 2
600,000
You should have answered 550,000.
550,000
500,000

19. Problem # 2 Now where would 549,085 go on this number line? 600,000
550,000
500,000

20. Problem # 2 Did you put 549,085 right here? 600,000 550,000 549,085
500,000

21. Problem # 2 So would 549,085 round to 500,000 or 600,000? 600,000
550,000
549,085
500,000

22. Problem # 2
≈ 500,000
600,000
550,000
549,085
500,000

23. Let’s try one last problem…
This time we are going to use rounding to help us estimate an addition problem.
We are going to estimate the answer to the following problem: 505, ,841.

24. Problem # 3
First lets round 505,341 to the nearest hundred thousand.

25. Problem # 3
What are the nearest hundred thousands to 505,341?

26. Problem # 3 You should have answered 500,000 and 600,000. 600,000

27. Problem # 3
600,000
What number is halfway between?
500,000

28. Problem # 3
600,000
Did you get 550,000?
550,000
500,000

29. Problem # 3
600,000
If 505,341 is located here do we round it to 500,000 or 600,000?
550,000
505,341
500,000

30. Problem # 3 That’s right! It would be 500,000.
600,000
That’s right! It would be 500,000.
What would we round 193,841 to?
550,000
505,341
500,000

31. Problem # 3
Let’s start by what are the two nearest hundred thousands to 193,841?

32. Problem # 3
200,000
Did you get 100,000 and 200,000?
100,000

33. Problem # 3
200,000
What number is halfway between these two?
100,000

34. Problem # 3
200,000
It is 150,000.
150,000
100,000

35. Problem # 3 If 193,841 is located here, what would you round it to?
200,000
If 193,841 is located here, what would you round it to?
193,841
150,000
100,000

36. Problem # 3
200,000
Did you say 200,000?
193,841
150,000
100,000

37. Problem # 3
So now we have the numbers 500,000 and 200,000. What are these numbers added together?

38. Problem # 3
Exactly! The answer to this problem should be around 700,000.

39. Time for Practice!
All right, it’s your turn. With a partner or independently complete #’s 1A, 2B, 2C, 3, and 5 on pages 45 and 46.