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Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 798 · 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 67 × 69? (a) 4900 (b) 49000 (c) 490
  2. 2.Best estimate of 155 + 259? (a) 700 (b) 300 (c) 500
  3. 3.Best estimate of 40 × 59? (a) 240 (b) 2400 (c) 24000
  4. 4.Best estimate of 640 + 474? (a) 1100 (b) 900 (c) 1300
  5. 5.Best estimate of 28 × 49? (a) 1500 (b) 150 (c) 15000
  6. 6.Best estimate of 188 + 757? (a) 1000 (b) 1200 (c) 800
  7. 7.Best estimate of 616 + 466? (a) 1300 (b) 900 (c) 1100
  8. 8.Best estimate of 267 + 291? (a) 600 (b) 800 (c) 400
  9. 9.Best estimate of 254 + 775? (a) 1100 (b) 1300 (c) 900
  10. 10.Best estimate of 476 + 180? (a) 700 (b) 900 (c) 500
  11. 11.Best estimate of 71 × 20? (a) 1400 (b) 140 (c) 14000
  12. 12.Best estimate of 191 + 127? (a) 500 (b) 100 (c) 300
  13. 13.Best estimate of 676 + 500? (a) 1000 (b) 1200 (c) 1400
  14. 14.Best estimate of 436 + 259? (a) 500 (b) 900 (c) 700
  15. 15.Best estimate of 643 + 190? (a) 1000 (b) 800 (c) 600
  16. 16.Best estimate of 209 + 213? (a) 400 (b) 600 (c) 200
  17. 17.Best estimate of 248 + 352? (a) 800 (b) 400 (c) 600
  18. 18.Best estimate of 93 × 66? (a) 6300 (b) 630 (c) 63000
  19. 19.Best estimate of 72 × 38? (a) 280 (b) 28000 (c) 2800
  20. 20.Best estimate of 357 + 125? (a) 300 (b) 500 (c) 700
  21. 21.Best estimate of 244 + 814? (a) 800 (b) 1000 (c) 1200
  22. 22.Best estimate of 511 + 602? (a) 1100 (b) 1300 (c) 900
  23. 23.Best estimate of 775 + 434? (a) 1400 (b) 1000 (c) 1200
  24. 24.Best estimate of 843 + 185? (a) 800 (b) 1000 (c) 1200
  25. 25.Best estimate of 61 × 13? (a) 60 (b) 6000 (c) 600
  26. 26.Best estimate of 123 + 573? (a) 900 (b) 500 (c) 700
  27. 27.Best estimate of 295 + 429? (a) 700 (b) 900 (c) 500
  28. 28.Best estimate of 60 × 21? (a) 1200 (b) 120 (c) 12000
  29. 29.Best estimate of 610 + 400? (a) 1200 (b) 800 (c) 1000
  30. 30.Best estimate of 29 × 51? (a) 150 (b) 15000 (c) 1500
  31. 31.Best estimate of 813 + 125? (a) 900 (b) 1100 (c) 700
  32. 32.Best estimate of 59 × 84? (a) 48000 (b) 4800 (c) 480
  33. 33.Best estimate of 698 + 394? (a) 1300 (b) 1100 (c) 900
  34. 34.Best estimate of 57 × 48? (a) 30000 (b) 300 (c) 3000
  35. 35.Best estimate of 414 + 643? (a) 1000 (b) 800 (c) 1200
  36. 36.Best estimate of 67 × 46? (a) 350 (b) 35000 (c) 3500
  37. 37.Best estimate of 89 × 26? (a) 2700 (b) 270 (c) 27000
  38. 38.Best estimate of 26 × 16? (a) 600 (b) 6000 (c) 60
  39. 39.Best estimate of 86 × 16? (a) 18000 (b) 180 (c) 1800
  40. 40.Best estimate of 77 × 28? (a) 24000 (b) 2400 (c) 240

Answer key

  1. 4900
  2. 500
  3. 2400
  4. 1100
  5. 1500
  6. 1000
  7. 1100
  8. 600
  9. 1100
  10. 700
  11. 1400
  12. 300
  13. 1200
  14. 700
  15. 800
  16. 400
  17. 600
  18. 6300
  19. 2800
  20. 500
  21. 1000
  22. 1100
  23. 1200
  24. 1000
  25. 600
  26. 700
  27. 700
  28. 1200
  29. 1000
  30. 1500
  31. 900
  32. 4800
  33. 1100
  34. 3000
  35. 1000
  36. 3500
  37. 2700
  38. 600
  39. 1800
  40. 2400

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