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Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 368 · 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 386 + 680? (a) 900 (b) 1300 (c) 1100
  2. 2.Best estimate of 34 × 19? (a) 600 (b) 60 (c) 6000
  3. 3.Best estimate of 50 × 22? (a) 10000 (b) 1000 (c) 100
  4. 4.Best estimate of 543 + 488? (a) 800 (b) 1000 (c) 1200
  5. 5.Best estimate of 482 + 630? (a) 900 (b) 1300 (c) 1100
  6. 6.Best estimate of 24 × 13? (a) 200 (b) 2000 (c) 20
  7. 7.Best estimate of 82 × 24? (a) 16000 (b) 160 (c) 1600
  8. 8.Best estimate of 690 + 340? (a) 1000 (b) 1200 (c) 800
  9. 9.Best estimate of 613 + 517? (a) 1100 (b) 1300 (c) 900
  10. 10.Best estimate of 36 × 64? (a) 2400 (b) 240 (c) 24000
  11. 11.Best estimate of 565 + 493? (a) 1100 (b) 1300 (c) 900
  12. 12.Best estimate of 181 + 380? (a) 400 (b) 600 (c) 800
  13. 13.Best estimate of 601 + 686? (a) 1500 (b) 1300 (c) 1100
  14. 14.Best estimate of 92 × 32? (a) 2700 (b) 27000 (c) 270
  15. 15.Best estimate of 96 × 44? (a) 400 (b) 40000 (c) 4000
  16. 16.Best estimate of 24 × 67? (a) 14000 (b) 1400 (c) 140
  17. 17.Best estimate of 91 × 77? (a) 720 (b) 7200 (c) 72000
  18. 18.Best estimate of 71 × 92? (a) 6300 (b) 63000 (c) 630
  19. 19.Best estimate of 724 + 842? (a) 1300 (b) 1500 (c) 1700
  20. 20.Best estimate of 373 + 702? (a) 900 (b) 1300 (c) 1100
  21. 21.Best estimate of 12 × 92? (a) 900 (b) 9000 (c) 90
  22. 22.Best estimate of 18 × 29? (a) 600 (b) 60 (c) 6000
  23. 23.Best estimate of 62 × 86? (a) 5400 (b) 540 (c) 54000
  24. 24.Best estimate of 80 × 44? (a) 32000 (b) 3200 (c) 320
  25. 25.Best estimate of 74 × 93? (a) 63000 (b) 630 (c) 6300
  26. 26.Best estimate of 641 + 703? (a) 1500 (b) 1100 (c) 1300
  27. 27.Best estimate of 673 + 471? (a) 1200 (b) 1000 (c) 1400
  28. 28.Best estimate of 59 × 48? (a) 30000 (b) 3000 (c) 300
  29. 29.Best estimate of 677 + 461? (a) 1200 (b) 1000 (c) 1400
  30. 30.Best estimate of 50 × 78? (a) 4000 (b) 400 (c) 40000
  31. 31.Best estimate of 629 + 630? (a) 1000 (b) 1200 (c) 1400
  32. 32.Best estimate of 183 + 184? (a) 200 (b) 400 (c) 600
  33. 33.Best estimate of 125 + 358? (a) 700 (b) 300 (c) 500
  34. 34.Best estimate of 409 + 287? (a) 700 (b) 500 (c) 900
  35. 35.Best estimate of 158 + 827? (a) 1000 (b) 800 (c) 1200
  36. 36.Best estimate of 584 + 237? (a) 800 (b) 600 (c) 1000
  37. 37.Best estimate of 94 × 27? (a) 2700 (b) 27000 (c) 270
  38. 38.Best estimate of 253 + 195? (a) 300 (b) 500 (c) 700
  39. 39.Best estimate of 14 × 86? (a) 900 (b) 9000 (c) 90
  40. 40.Best estimate of 149 + 522? (a) 600 (b) 800 (c) 400

Answer key

  1. 1100
  2. 600
  3. 1000
  4. 1000
  5. 1100
  6. 200
  7. 1600
  8. 1000
  9. 1100
  10. 2400
  11. 1100
  12. 600
  13. 1300
  14. 2700
  15. 4000
  16. 1400
  17. 7200
  18. 6300
  19. 1500
  20. 1100
  21. 900
  22. 600
  23. 5400
  24. 3200
  25. 6300
  26. 1300
  27. 1200
  28. 3000
  29. 1200
  30. 4000
  31. 1200
  32. 400
  33. 500
  34. 700
  35. 1000
  36. 800
  37. 2700
  38. 500
  39. 900
  40. 600

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