Round to Nearest 10 or 100 - 3rd Grade Math

1. What happens to the digits to the right of the rounding place after rounding to the nearest $10$ or $100$?

   All digits to the right become $0$. Rounding replaces smaller place values with zeros.

2. What is $399$ rounded to the nearest $100$?

   $400$. Tens digit $9$ is $≥5$, so round up to $400$.

3. Find and correct the error: $389$ rounded to the nearest $100$ is written as $300$.

   Correct rounding: $389$ rounds to $400$. Tens digit $8$ is $5$ or more, so must round up to $400$, not down.

4. What rule tells you when to round down when rounding to the nearest $10$?

   Round down if the ones digit is $0$–$4$. Ones digit $4$ or less keeps the same ten.

5. What is the rounding rule when the checked digit is $5$ through $9$?

   Round up; increase the rounding digit by $1$. Digits $5$-$9$ mean the number is closer to the higher rounding target.

6. What digit do you check to round a whole number to the nearest $100$?

   Check the tens digit. The tens place determines if you round the hundreds place up or down.

7. What is $104$ rounded to the nearest $10$?

   $100$. Ones digit $4$ is less than $5$, so round down to $100$.

8. What rule tells you when to round down when rounding to the nearest $100$?

   Round down if the tens digit is $0$–$4$. Tens digit $4$ or less keeps the same hundred.

9. What is $75$ rounded to the nearest $10$?

   $80$. Ones digit $5$ means round up from $70$ to $80$.

10. What is $149$ rounded to the nearest $100$?

    $100$. Tens digit $4$ is $<5$, so round down to $100$.

11. Which option is $768$ rounded to the nearest $100$: $700$ or $800$?

    $800$. Tens digit $6$ is $≥5$, so round up.

12. What is $149$ rounded to the nearest $10$?

    $150$. Ones digit $9$ is $5$ or more, so round up from $140$ to $150$.

13. What digits replace the digits to the right after rounding to the nearest $10$?

    Replace the ones digit with $0$. All digits to the right of the tens place become $0$.

14. Which option is $742$ rounded to the nearest $100$: $700$ or $800$?

    $700$. Tens digit $4$ is $<5$, so round down.

15. What is $42$ rounded to the nearest $10$?

    $40$. Ones digit $2$ is $<5$, so round down to $40$.

16. What is $47$ rounded to the nearest $10$?

    $50$. Ones digit $7$ is $≥5$, so round up from $40$ to $50$.

17. What is $150$ rounded to the nearest $100$?

    $200$. Tens digit $5$ is $≥5$, so round up to $200$.

18. What digit do you look at to round a number to the nearest $10$?

    Look at the ones digit. The ones place determines if you round up or down.

19. What is $450$ rounded to the nearest $100$?

    $500$. Tens digit $5$ means round up from $400$ to $500$.

20. What is $499$ rounded to the nearest $100$?

    $500$. Tens digit $9$ is $5$ or more, so round up from $400$ to $500$.

21. What is $150$ rounded to the nearest $10$?

    $150$. Already ends in $0$, so it stays $150$.

22. What is $500$ rounded to the nearest $100$?

    $500$. Already ends in $00$, so it stays $500$.

23. What rule tells you when to round up to the next hundred when rounding to the nearest $100$?

    Round up if the tens digit is $5$–$9$. Tens digit $5$ or more means round to the next hundred.

24. What is $68$ rounded to the nearest $10$?

    $70$. Ones digit $8$ is $5$ or more, so round up from $60$ to $70$.

25. Find and correct the rounding error: $235$ rounded to the nearest $10$ is written as $230$.

    Correct rounding: $235$ rounds to $240$. Ones digit $5$ means round up, not down.

26. What rule tells you when to round up to the next ten when rounding to the nearest $10$?

    Round up if the ones digit is $5$–$9$. Ones digit $5$ or more means round to the next ten.

27. Which is correct: $267$ rounded to the nearest $10$ is $260$ or $270$?

    $270$. Ones digit $7$ is $5$ or more, so round up to $270$.

28. Which option is $284$ rounded to the nearest $10$: $280$ or $290$?

    $280$. Ones digit $4$ is $<5$, so round down.

29. Which option is $286$ rounded to the nearest $10$: $280$ or $290$?

    $290$. Ones digit $6$ is $≥5$, so round up.

30. What is $381$ rounded to the nearest $100$?

    $400$. Tens digit $8$ is $5$ or more, so round up from $300$ to $400$.

31. What is the rounding rule when the checked digit is $0$ through $4$?

    Round down; keep the rounding digit the same. Digits $0$-$4$ mean the number is closer to the lower rounding target.

32. What is $65$ rounded to the nearest $10$?

    $70$. Ones digit $5$ is $≥5$, so round up from $60$ to $70$.

33. What is $342$ rounded to the nearest $100$?

    $300$. Tens digit $4$ is less than $5$, so round down to $300$.

34. What digits replace the digits to the right after rounding to the nearest $100$?

    Replace the tens and ones digits with $0$. All digits to the right of the hundreds place become $0$.

35. What is $90$ rounded to the nearest $10$?

    $90$. Already ends in $0$, so it stays $90$.

36. What is $62$ rounded to the nearest $10$?

    $60$. Ones digit $2$ is less than $5$, so round down to $60$.

37. What is $372$ rounded to the nearest $100$?

    $400$. Tens digit $7$ is $≥5$, so round up to $400$.

38. What digit do you check to round a whole number to the nearest $10$?

    Check the ones digit. The ones place determines if you round the tens place up or down.

39. Which is correct: $732$ rounded to the nearest $100$ is $700$ or $800$?

    $700$. Tens digit $3$ is less than $5$, so round down to $700$.

40. What digit do you look at to round a number to the nearest $100$?

    Look at the tens digit. The tens place determines if you round up or down.

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