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Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 133 · 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 758 + 182? (a) 1200 (b) 1000 (c) 800
  2. 2.Best estimate of 93 × 37? (a) 36000 (b) 360 (c) 3600
  3. 3.Best estimate of 196 + 615? (a) 600 (b) 1000 (c) 800
  4. 4.Best estimate of 295 + 536? (a) 1000 (b) 600 (c) 800
  5. 5.Best estimate of 775 + 280? (a) 1100 (b) 900 (c) 1300
  6. 6.Best estimate of 43 × 17? (a) 80 (b) 800 (c) 8000
  7. 7.Best estimate of 807 + 565? (a) 1200 (b) 1600 (c) 1400
  8. 8.Best estimate of 97 × 88? (a) 90000 (b) 900 (c) 9000
  9. 9.Best estimate of 279 + 227? (a) 700 (b) 300 (c) 500
  10. 10.Best estimate of 97 × 21? (a) 200 (b) 2000 (c) 20000
  11. 11.Best estimate of 187 + 484? (a) 500 (b) 700 (c) 900
  12. 12.Best estimate of 232 + 265? (a) 700 (b) 300 (c) 500
  13. 13.Best estimate of 62 × 74? (a) 42000 (b) 420 (c) 4200
  14. 14.Best estimate of 176 + 739? (a) 900 (b) 700 (c) 1100
  15. 15.Best estimate of 62 × 77? (a) 48000 (b) 480 (c) 4800
  16. 16.Best estimate of 96 × 26? (a) 300 (b) 3000 (c) 30000
  17. 17.Best estimate of 206 + 335? (a) 500 (b) 300 (c) 700
  18. 18.Best estimate of 31 × 19? (a) 600 (b) 60 (c) 6000
  19. 19.Best estimate of 194 + 677? (a) 1100 (b) 900 (c) 700
  20. 20.Best estimate of 84 × 32? (a) 240 (b) 24000 (c) 2400
  21. 21.Best estimate of 396 + 429? (a) 1000 (b) 600 (c) 800
  22. 22.Best estimate of 245 + 178? (a) 600 (b) 400 (c) 200
  23. 23.Best estimate of 66 × 12? (a) 7000 (b) 700 (c) 70
  24. 24.Best estimate of 96 × 66? (a) 7000 (b) 70000 (c) 700
  25. 25.Best estimate of 543 + 515? (a) 1000 (b) 800 (c) 1200
  26. 26.Best estimate of 661 + 451? (a) 1000 (b) 1200 (c) 1400
  27. 27.Best estimate of 539 + 612? (a) 1100 (b) 900 (c) 1300
  28. 28.Best estimate of 66 × 56? (a) 4200 (b) 42000 (c) 420
  29. 29.Best estimate of 211 + 667? (a) 700 (b) 900 (c) 1100
  30. 30.Best estimate of 33 × 86? (a) 270 (b) 2700 (c) 27000
  31. 31.Best estimate of 38 × 69? (a) 28000 (b) 280 (c) 2800
  32. 32.Best estimate of 91 × 28? (a) 27000 (b) 270 (c) 2700
  33. 33.Best estimate of 58 × 96? (a) 60000 (b) 600 (c) 6000
  34. 34.Best estimate of 799 + 422? (a) 1400 (b) 1200 (c) 1000
  35. 35.Best estimate of 66 × 89? (a) 6300 (b) 63000 (c) 630
  36. 36.Best estimate of 21 × 62? (a) 12000 (b) 120 (c) 1200
  37. 37.Best estimate of 48 × 40? (a) 20000 (b) 200 (c) 2000
  38. 38.Best estimate of 74 × 46? (a) 350 (b) 3500 (c) 35000
  39. 39.Best estimate of 27 × 83? (a) 240 (b) 2400 (c) 24000
  40. 40.Best estimate of 72 × 42? (a) 280 (b) 28000 (c) 2800

Answer key

  1. 1000
  2. 3600
  3. 800
  4. 800
  5. 1100
  6. 800
  7. 1400
  8. 9000
  9. 500
  10. 2000
  11. 700
  12. 500
  13. 4200
  14. 900
  15. 4800
  16. 3000
  17. 500
  18. 600
  19. 900
  20. 2400
  21. 800
  22. 400
  23. 700
  24. 7000
  25. 1000
  26. 1200
  27. 1100
  28. 4200
  29. 900
  30. 2700
  31. 2800
  32. 2700
  33. 6000
  34. 1200
  35. 6300
  36. 1200
  37. 2000
  38. 3500
  39. 2400
  40. 2800

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