2. Rounding Numbers to the Closest Ten by Debbie Wilks

3. When you find the ten that is closest to a number, you are rounding.

4. For example, 40 is the closest ten to 36. So, 36 is rounded to 40.

5. Let’s think about a number line like a roller coaster.

6. You might think about a number line that looks like this: 103020

7. On this number line, what number would come half way between 10 and 20? 103020 15

8. What number would come half way between 20 and 30? 103020 1525

9. What ten would be next? 103020 152535 40 What number would be half way between?

10. Can you guess about where 17 would be on this number line? 103020 152535 40 17

11. 103020 152535 40 17 If the roller coaster stopped, what number would it roll to?

12. Can you guess about where 23 would be on this number line? 103020 152535 40 23

13. 103020 152535 40 23 If the roller coaster stopped, what number would it roll to?

14. Can you guess about where 36 would be on this number line? 103020 152535 40 36

15. What would you round it to? 103020 152535 40 36

16. Can you guess about where 41 would be on this number line? 103020 152535 40 41

17. What would you round it to? 103020 152535 40 41

18. Can you guess about where 19 would be on this number line? 103020 152535 40 19

19. Can you guess about where 19 would be on this number line? 103020 152535 40 19

20. 103020 152535 40 19 What would you round it to?

21. What about a number like 25? It’s right in the middle! 103020 152535 40

22. Our rule is to round to the next ten. 103020 152535 40

23. 103020 152535 40 Tell a number that would round to 10. 11 12 13 14

24. When you round to the closest ten, look in the ones place. If it has 1,2,3, or 4 round down. If it has 5, 6,7, 8, or 9 round up.

25. To round remember this rhyme, 5, 6, 7, 8, 9 GO UP all the time!!

26. Rounding numbers is so fun, We will do it 'till we're done. If a number's 1-4, Round it down right through the floor. If a number's 5-9, Round it up it is just fine. Round up, Round down, 1,2,3,4 --- 1-2, 3-4

27. Now it’s your turn! You can get some help from the number line.

28. What ten is closest to 56? Put your bean on the closest ten.

29. What ten is closest to 79? Put your bean on the closest ten.

30. What ten is closest to 83? Put your bean on the closest ten.

31. What ten is closest to 99? Put your bean on the closest ten.

32. What ten is closest to 65? Put your bean on the closest ten.

33. What ten is closest to 94? Put your bean on the closest ten.

34. Are you roller coaster ready for an assignment?