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Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 636 · 40 questions
TalentJR

How to do it in your head (Round, then work): Round each number: 2-digit numbers to the nearest ten, 3-digit numbers to the nearest hundred. Do the easy sum with the round numbers. Choose the option closest to your estimate.

NameDateTime takenScore ___ / 40
  1. 1.Best estimate of 562 + 583? (a) 1200 (b) 1400 (c) 1000
  2. 2.Best estimate of 337 + 782? (a) 900 (b) 1300 (c) 1100
  3. 3.Best estimate of 329 + 834? (a) 900 (b) 1100 (c) 1300
  4. 4.Best estimate of 76 × 60? (a) 4800 (b) 480 (c) 48000
  5. 5.Best estimate of 96 × 86? (a) 900 (b) 9000 (c) 90000
  6. 6.Best estimate of 87 × 16? (a) 18000 (b) 1800 (c) 180
  7. 7.Best estimate of 73 × 89? (a) 63000 (b) 6300 (c) 630
  8. 8.Best estimate of 552 + 716? (a) 1100 (b) 1300 (c) 1500
  9. 9.Best estimate of 41 × 56? (a) 240 (b) 24000 (c) 2400
  10. 10.Best estimate of 82 × 26? (a) 2400 (b) 24000 (c) 240
  11. 11.Best estimate of 874 + 576? (a) 1500 (b) 1300 (c) 1700
  12. 12.Best estimate of 79 × 46? (a) 40000 (b) 4000 (c) 400
  13. 13.Best estimate of 549 + 406? (a) 1100 (b) 900 (c) 700
  14. 14.Best estimate of 26 × 23? (a) 600 (b) 6000 (c) 60
  15. 15.Best estimate of 782 + 470? (a) 1500 (b) 1300 (c) 1100
  16. 16.Best estimate of 715 + 464? (a) 1400 (b) 1000 (c) 1200
  17. 17.Best estimate of 283 + 459? (a) 800 (b) 1000 (c) 600
  18. 18.Best estimate of 455 + 436? (a) 900 (b) 1100 (c) 700
  19. 19.Best estimate of 33 × 77? (a) 2400 (b) 24000 (c) 240
  20. 20.Best estimate of 497 + 384? (a) 700 (b) 900 (c) 1100
  21. 21.Best estimate of 718 + 383? (a) 1300 (b) 1100 (c) 900
  22. 22.Best estimate of 56 × 61? (a) 36000 (b) 360 (c) 3600
  23. 23.Best estimate of 488 + 353? (a) 700 (b) 900 (c) 1100
  24. 24.Best estimate of 210 + 751? (a) 1200 (b) 1000 (c) 800
  25. 25.Best estimate of 76 × 36? (a) 32000 (b) 320 (c) 3200
  26. 26.Best estimate of 42 × 41? (a) 160 (b) 1600 (c) 16000
  27. 27.Best estimate of 82 × 91? (a) 72000 (b) 720 (c) 7200
  28. 28.Best estimate of 93 × 37? (a) 36000 (b) 360 (c) 3600
  29. 29.Best estimate of 66 × 62? (a) 420 (b) 4200 (c) 42000
  30. 30.Best estimate of 64 × 93? (a) 540 (b) 5400 (c) 54000
  31. 31.Best estimate of 175 + 783? (a) 1200 (b) 1000 (c) 800
  32. 32.Best estimate of 34 × 84? (a) 24000 (b) 240 (c) 2400
  33. 33.Best estimate of 36 × 23? (a) 80 (b) 800 (c) 8000
  34. 34.Best estimate of 29 × 58? (a) 1800 (b) 180 (c) 18000
  35. 35.Best estimate of 147 + 309? (a) 600 (b) 400 (c) 200
  36. 36.Best estimate of 52 × 96? (a) 5000 (b) 50000 (c) 500
  37. 37.Best estimate of 69 × 90? (a) 63000 (b) 6300 (c) 630
  38. 38.Best estimate of 52 × 74? (a) 3500 (b) 350 (c) 35000
  39. 39.Best estimate of 743 + 502? (a) 1400 (b) 1000 (c) 1200
  40. 40.Best estimate of 24 × 73? (a) 140 (b) 1400 (c) 14000

Answer key

  1. 1200
  2. 1100
  3. 1100
  4. 4800
  5. 9000
  6. 1800
  7. 6300
  8. 1300
  9. 2400
  10. 2400
  11. 1500
  12. 4000
  13. 900
  14. 600
  15. 1300
  16. 1200
  17. 800
  18. 900
  19. 2400
  20. 900
  21. 1100
  22. 3600
  23. 900
  24. 1000
  25. 3200
  26. 1600
  27. 7200
  28. 3600
  29. 4200
  30. 5400
  31. 1000
  32. 2400
  33. 800
  34. 1800
  35. 400
  36. 5000
  37. 6300
  38. 3500
  39. 1200
  40. 1400

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