Cardinal Math

Grade 3 · 3.NBT.1 · sheet 28 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 255 to the nearest ten
  2. 2 Round 390 to the nearest hundred
  3. 3 Round 392 to the nearest hundred
  4. 4 Round 955 to the nearest ten
  5. 5 Round 663 to the nearest hundred
  6. 6 Round 289 to the nearest ten
  7. 7 Round 770 to the nearest hundred
  8. 8 Round 318 to the nearest ten
  9. 9 Round 646 to the nearest ten
  10. 10 Round 250 to the nearest hundred
  11. 11 Round 828 to the nearest hundred
  12. 12 Round 25 to the nearest ten
  13. 13 Round 437 to the nearest ten
  14. 14 Round 650 to the nearest hundred
  15. 15 Round 592 to the nearest hundred
  16. 16 Round 403 to the nearest ten
  17. 17 Round 478 to the nearest ten
  18. 18 Round 450 to the nearest hundred
  19. 19 Round 343 to the nearest ten
  20. 20 Round 681 to the nearest hundred
Cardinal Math · sheet 28 key: cardinalmath.com/worksheets/rounding/28/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 (17 problems), rounding at the wrong place (9 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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