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Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 403 · 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 54 × 62? (a) 300 (b) 3000 (c) 30000
  2. 2.Best estimate of 43 × 86? (a) 360 (b) 36000 (c) 3600
  3. 3.Best estimate of 691 + 698? (a) 1600 (b) 1200 (c) 1400
  4. 4.Best estimate of 545 + 512? (a) 1200 (b) 800 (c) 1000
  5. 5.Best estimate of 22 × 74? (a) 14000 (b) 140 (c) 1400
  6. 6.Best estimate of 92 × 64? (a) 5400 (b) 540 (c) 54000
  7. 7.Best estimate of 702 + 484? (a) 1200 (b) 1400 (c) 1000
  8. 8.Best estimate of 280 + 328? (a) 600 (b) 400 (c) 800
  9. 9.Best estimate of 16 × 62? (a) 1200 (b) 12000 (c) 120
  10. 10.Best estimate of 86 × 34? (a) 27000 (b) 270 (c) 2700
  11. 11.Best estimate of 124 + 213? (a) 500 (b) 300 (c) 100
  12. 12.Best estimate of 195 + 691? (a) 1100 (b) 900 (c) 700
  13. 13.Best estimate of 748 + 548? (a) 1200 (b) 1400 (c) 1000
  14. 14.Best estimate of 76 × 27? (a) 24000 (b) 240 (c) 2400
  15. 15.Best estimate of 725 + 348? (a) 1200 (b) 800 (c) 1000
  16. 16.Best estimate of 581 + 726? (a) 1500 (b) 1300 (c) 1100
  17. 17.Best estimate of 483 + 387? (a) 1100 (b) 700 (c) 900
  18. 18.Best estimate of 508 + 375? (a) 900 (b) 700 (c) 1100
  19. 19.Best estimate of 453 + 555? (a) 1100 (b) 1300 (c) 900
  20. 20.Best estimate of 41 × 86? (a) 3600 (b) 360 (c) 36000
  21. 21.Best estimate of 183 + 177? (a) 200 (b) 600 (c) 400
  22. 22.Best estimate of 29 × 96? (a) 3000 (b) 30000 (c) 300
  23. 23.Best estimate of 206 + 493? (a) 700 (b) 900 (c) 500
  24. 24.Best estimate of 154 + 670? (a) 900 (b) 700 (c) 1100
  25. 25.Best estimate of 872 + 188? (a) 1300 (b) 900 (c) 1100
  26. 26.Best estimate of 97 × 12? (a) 1000 (b) 100 (c) 10000
  27. 27.Best estimate of 56 × 47? (a) 30000 (b) 3000 (c) 300
  28. 28.Best estimate of 12 × 67? (a) 7000 (b) 700 (c) 70
  29. 29.Best estimate of 46 × 70? (a) 3500 (b) 35000 (c) 350
  30. 30.Best estimate of 321 + 554? (a) 1100 (b) 700 (c) 900
  31. 31.Best estimate of 23 × 72? (a) 1400 (b) 14000 (c) 140
  32. 32.Best estimate of 231 + 329? (a) 500 (b) 700 (c) 300
  33. 33.Best estimate of 46 × 54? (a) 2500 (b) 25000 (c) 250
  34. 34.Best estimate of 28 × 76? (a) 24000 (b) 240 (c) 2400
  35. 35.Best estimate of 33 × 49? (a) 15000 (b) 1500 (c) 150
  36. 36.Best estimate of 466 + 689? (a) 1400 (b) 1200 (c) 1000
  37. 37.Best estimate of 369 + 846? (a) 1000 (b) 1400 (c) 1200
  38. 38.Best estimate of 76 × 30? (a) 24000 (b) 240 (c) 2400
  39. 39.Best estimate of 867 + 445? (a) 1300 (b) 1500 (c) 1100
  40. 40.Best estimate of 86 × 42? (a) 360 (b) 36000 (c) 3600

Answer key

  1. 3000
  2. 3600
  3. 1400
  4. 1000
  5. 1400
  6. 5400
  7. 1200
  8. 600
  9. 1200
  10. 2700
  11. 300
  12. 900
  13. 1200
  14. 2400
  15. 1000
  16. 1300
  17. 900
  18. 900
  19. 1100
  20. 3600
  21. 400
  22. 3000
  23. 700
  24. 900
  25. 1100
  26. 1000
  27. 3000
  28. 700
  29. 3500
  30. 900
  31. 1400
  32. 500
  33. 2500
  34. 2400
  35. 1500
  36. 1200
  37. 1200
  38. 2400
  39. 1300
  40. 3600

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