← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 984 · 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 58 × 16? (a) 12000 (b) 1200 (c) 120
  2. 2.Best estimate of 31 × 49? (a) 1500 (b) 150 (c) 15000
  3. 3.Best estimate of 74 × 58? (a) 4200 (b) 420 (c) 42000
  4. 4.Best estimate of 876 + 790? (a) 1500 (b) 1700 (c) 1900
  5. 5.Best estimate of 374 + 249? (a) 800 (b) 600 (c) 400
  6. 6.Best estimate of 340 + 165? (a) 500 (b) 700 (c) 300
  7. 7.Best estimate of 444 + 729? (a) 1100 (b) 1300 (c) 900
  8. 8.Best estimate of 170 + 121? (a) 300 (b) 100 (c) 500
  9. 9.Best estimate of 196 + 821? (a) 800 (b) 1000 (c) 1200
  10. 10.Best estimate of 858 + 403? (a) 1500 (b) 1100 (c) 1300
  11. 11.Best estimate of 233 + 228? (a) 400 (b) 600 (c) 200
  12. 12.Best estimate of 48 × 34? (a) 150 (b) 15000 (c) 1500
  13. 13.Best estimate of 44 × 60? (a) 240 (b) 24000 (c) 2400
  14. 14.Best estimate of 237 + 621? (a) 1000 (b) 800 (c) 600
  15. 15.Best estimate of 19 × 79? (a) 16000 (b) 1600 (c) 160
  16. 16.Best estimate of 412 + 668? (a) 900 (b) 1300 (c) 1100
  17. 17.Best estimate of 488 + 138? (a) 800 (b) 400 (c) 600
  18. 18.Best estimate of 731 + 641? (a) 1300 (b) 1100 (c) 1500
  19. 19.Best estimate of 33 × 41? (a) 12000 (b) 120 (c) 1200
  20. 20.Best estimate of 87 × 27? (a) 27000 (b) 270 (c) 2700
  21. 21.Best estimate of 216 + 734? (a) 1100 (b) 900 (c) 700
  22. 22.Best estimate of 545 + 167? (a) 500 (b) 700 (c) 900
  23. 23.Best estimate of 71 × 26? (a) 21000 (b) 2100 (c) 210
  24. 24.Best estimate of 61 × 66? (a) 4200 (b) 42000 (c) 420
  25. 25.Best estimate of 52 × 14? (a) 5000 (b) 500 (c) 50
  26. 26.Best estimate of 392 + 486? (a) 700 (b) 900 (c) 1100
  27. 27.Best estimate of 48 × 88? (a) 4500 (b) 45000 (c) 450
  28. 28.Best estimate of 14 × 86? (a) 9000 (b) 900 (c) 90
  29. 29.Best estimate of 28 × 29? (a) 90 (b) 900 (c) 9000
  30. 30.Best estimate of 16 × 52? (a) 10000 (b) 1000 (c) 100
  31. 31.Best estimate of 251 + 633? (a) 900 (b) 1100 (c) 700
  32. 32.Best estimate of 491 + 468? (a) 1000 (b) 1200 (c) 800
  33. 33.Best estimate of 83 × 48? (a) 400 (b) 40000 (c) 4000
  34. 34.Best estimate of 537 + 151? (a) 700 (b) 500 (c) 900
  35. 35.Best estimate of 128 + 552? (a) 500 (b) 700 (c) 900
  36. 36.Best estimate of 582 + 731? (a) 1300 (b) 1100 (c) 1500
  37. 37.Best estimate of 44 × 38? (a) 16000 (b) 1600 (c) 160
  38. 38.Best estimate of 34 × 20? (a) 6000 (b) 600 (c) 60
  39. 39.Best estimate of 434 + 410? (a) 800 (b) 600 (c) 1000
  40. 40.Best estimate of 60 × 59? (a) 36000 (b) 360 (c) 3600

Answer key

  1. 1200
  2. 1500
  3. 4200
  4. 1700
  5. 600
  6. 500
  7. 1100
  8. 300
  9. 1000
  10. 1300
  11. 400
  12. 1500
  13. 2400
  14. 800
  15. 1600
  16. 1100
  17. 600
  18. 1300
  19. 1200
  20. 2700
  21. 900
  22. 700
  23. 2100
  24. 4200
  25. 500
  26. 900
  27. 4500
  28. 900
  29. 900
  30. 1000
  31. 900
  32. 1000
  33. 4000
  34. 700
  35. 700
  36. 1300
  37. 1600
  38. 600
  39. 800
  40. 3600

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