← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 947 · 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 78 × 78? (a) 64000 (b) 6400 (c) 640
  2. 2.Best estimate of 292 + 148? (a) 600 (b) 200 (c) 400
  3. 3.Best estimate of 493 + 280? (a) 600 (b) 1000 (c) 800
  4. 4.Best estimate of 156 + 641? (a) 1000 (b) 600 (c) 800
  5. 5.Best estimate of 836 + 666? (a) 1300 (b) 1500 (c) 1700
  6. 6.Best estimate of 847 + 133? (a) 1100 (b) 700 (c) 900
  7. 7.Best estimate of 172 + 772? (a) 1000 (b) 800 (c) 1200
  8. 8.Best estimate of 67 × 50? (a) 35000 (b) 350 (c) 3500
  9. 9.Best estimate of 32 × 67? (a) 2100 (b) 21000 (c) 210
  10. 10.Best estimate of 130 + 648? (a) 500 (b) 700 (c) 900
  11. 11.Best estimate of 394 + 852? (a) 1100 (b) 1500 (c) 1300
  12. 12.Best estimate of 317 + 807? (a) 1300 (b) 1100 (c) 900
  13. 13.Best estimate of 54 × 50? (a) 2500 (b) 25000 (c) 250
  14. 14.Best estimate of 12 × 63? (a) 600 (b) 6000 (c) 60
  15. 15.Best estimate of 64 × 66? (a) 420 (b) 42000 (c) 4200
  16. 16.Best estimate of 71 × 79? (a) 56000 (b) 5600 (c) 560
  17. 17.Best estimate of 761 + 251? (a) 1100 (b) 900 (c) 1300
  18. 18.Best estimate of 17 × 13? (a) 200 (b) 2000 (c) 20
  19. 19.Best estimate of 14 × 60? (a) 60 (b) 600 (c) 6000
  20. 20.Best estimate of 16 × 24? (a) 400 (b) 40 (c) 4000
  21. 21.Best estimate of 495 + 315? (a) 800 (b) 600 (c) 1000
  22. 22.Best estimate of 317 + 842? (a) 1300 (b) 1100 (c) 900
  23. 23.Best estimate of 98 × 37? (a) 400 (b) 4000 (c) 40000
  24. 24.Best estimate of 348 + 633? (a) 900 (b) 1100 (c) 700
  25. 25.Best estimate of 97 × 57? (a) 600 (b) 6000 (c) 60000
  26. 26.Best estimate of 795 + 767? (a) 1800 (b) 1400 (c) 1600
  27. 27.Best estimate of 26 × 56? (a) 180 (b) 1800 (c) 18000
  28. 28.Best estimate of 331 + 147? (a) 200 (b) 400 (c) 600
  29. 29.Best estimate of 289 + 357? (a) 500 (b) 700 (c) 900
  30. 30.Best estimate of 97 × 87? (a) 9000 (b) 90000 (c) 900
  31. 31.Best estimate of 33 × 16? (a) 6000 (b) 60 (c) 600
  32. 32.Best estimate of 803 + 597? (a) 1200 (b) 1600 (c) 1400
  33. 33.Best estimate of 88 × 64? (a) 54000 (b) 540 (c) 5400
  34. 34.Best estimate of 91 × 53? (a) 4500 (b) 45000 (c) 450
  35. 35.Best estimate of 443 + 499? (a) 700 (b) 900 (c) 1100
  36. 36.Best estimate of 734 + 264? (a) 1000 (b) 800 (c) 1200
  37. 37.Best estimate of 89 × 29? (a) 2700 (b) 270 (c) 27000
  38. 38.Best estimate of 52 × 32? (a) 15000 (b) 1500 (c) 150
  39. 39.Best estimate of 789 + 623? (a) 1600 (b) 1400 (c) 1200
  40. 40.Best estimate of 692 + 803? (a) 1500 (b) 1300 (c) 1700

Answer key

  1. 6400
  2. 400
  3. 800
  4. 800
  5. 1500
  6. 900
  7. 1000
  8. 3500
  9. 2100
  10. 700
  11. 1300
  12. 1100
  13. 2500
  14. 600
  15. 4200
  16. 5600
  17. 1100
  18. 200
  19. 600
  20. 400
  21. 800
  22. 1100
  23. 4000
  24. 900
  25. 6000
  26. 1600
  27. 1800
  28. 400
  29. 700
  30. 9000
  31. 600
  32. 1400
  33. 5400
  34. 4500
  35. 900
  36. 1000
  37. 2700
  38. 1500
  39. 1400
  40. 1500

Free mental maths lessons, practice and worksheets at talentjr.in/mental-maths