Cardinal Math

Grade 3 · 3.NBT.1 · sheet 21 of 30

Rounding to the nearest ten and hundred

A printable worksheet, new every day, with a key that names the mistake.

  • Ten numbers to round to the nearest ten and ten to the nearest hundred, three of each sitting exactly halfway.
  • The key names the two usual mistakes: cutting the number off instead of rounding, and looking at the wrong digit.
Answer key Another sheet →

Rounding to the nearest ten and hundred

Round each number. Halfway rounds up.

Name Date
  1. 1 Round 75 to the nearest ten
  2. 2 Round 651 to the nearest hundred
  3. 3 Round 550 to the nearest hundred
  4. 4 Round 869 to the nearest ten
  5. 5 Round 403 to the nearest hundred
  6. 6 Round 176 to the nearest ten
  7. 7 Round 955 to the nearest ten
  8. 8 Round 389 to the nearest ten
  9. 9 Round 126 to the nearest ten
  10. 10 Round 845 to the nearest ten
  11. 11 Round 471 to the nearest hundred
  12. 12 Round 295 to the nearest hundred
  13. 13 Round 750 to the nearest hundred
  14. 14 Round 858 to the nearest hundred
  15. 15 Round 250 to the nearest hundred
  16. 16 Round 139 to the nearest ten
  17. 17 Round 633 to the nearest hundred
  18. 18 Round 480 to the nearest hundred
  19. 19 Round 477 to the nearest ten
  20. 20 Round 497 to the nearest ten
Cardinal Math · sheet 21 key: cardinalmath.com/worksheets/rounding/21/key/

The app does this live.

It picks the next problem from the last answer, skips ahead or doubles back, and animates the teaching instead of handing over a rule. Inside the app the same patterns the key names are caught as your child plays.

How to use the key

Mark the sheet against the key. Beside each answer it lists what the known mistakes would have written. One wrong answer is a slip. The same pattern three times is a rule your child is following, and the guide says what to do about it tonight.

On this sheet the key can tell apart: cutting the number off instead of rounding (18 problems), rounding at the wrong place (8 problems).

Cardinal Math watches for all of these, every day.

Inside the app the same patterns are caught as your child plays, across the whole of K to grade 5, and explained to you in plain words. One price, no ads, no streaks. Coming to iPhone and iPad.

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