← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 581 · 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 687 + 249? (a) 900 (b) 700 (c) 1100
  2. 2.Best estimate of 659 + 521? (a) 1200 (b) 1400 (c) 1000
  3. 3.Best estimate of 46 × 33? (a) 150 (b) 15000 (c) 1500
  4. 4.Best estimate of 776 + 479? (a) 1500 (b) 1100 (c) 1300
  5. 5.Best estimate of 818 + 508? (a) 1300 (b) 1100 (c) 1500
  6. 6.Best estimate of 222 + 131? (a) 100 (b) 500 (c) 300
  7. 7.Best estimate of 62 × 71? (a) 42000 (b) 420 (c) 4200
  8. 8.Best estimate of 41 × 79? (a) 3200 (b) 32000 (c) 320
  9. 9.Best estimate of 68 × 98? (a) 7000 (b) 700 (c) 70000
  10. 10.Best estimate of 77 × 71? (a) 56000 (b) 5600 (c) 560
  11. 11.Best estimate of 50 × 33? (a) 1500 (b) 15000 (c) 150
  12. 12.Best estimate of 28 × 78? (a) 24000 (b) 240 (c) 2400
  13. 13.Best estimate of 53 × 59? (a) 3000 (b) 300 (c) 30000
  14. 14.Best estimate of 61 × 14? (a) 6000 (b) 60 (c) 600
  15. 15.Best estimate of 86 × 38? (a) 3600 (b) 36000 (c) 360
  16. 16.Best estimate of 52 × 69? (a) 3500 (b) 35000 (c) 350
  17. 17.Best estimate of 19 × 92? (a) 1800 (b) 18000 (c) 180
  18. 18.Best estimate of 599 + 686? (a) 1100 (b) 1500 (c) 1300
  19. 19.Best estimate of 40 × 88? (a) 36000 (b) 360 (c) 3600
  20. 20.Best estimate of 97 × 83? (a) 800 (b) 8000 (c) 80000
  21. 21.Best estimate of 786 + 283? (a) 900 (b) 1300 (c) 1100
  22. 22.Best estimate of 38 × 76? (a) 32000 (b) 3200 (c) 320
  23. 23.Best estimate of 78 × 13? (a) 800 (b) 80 (c) 8000
  24. 24.Best estimate of 506 + 754? (a) 1500 (b) 1300 (c) 1100
  25. 25.Best estimate of 26 × 73? (a) 210 (b) 2100 (c) 21000
  26. 26.Best estimate of 857 + 330? (a) 1200 (b) 1400 (c) 1000
  27. 27.Best estimate of 19 × 89? (a) 18000 (b) 180 (c) 1800
  28. 28.Best estimate of 318 + 801? (a) 1300 (b) 1100 (c) 900
  29. 29.Best estimate of 583 + 682? (a) 1100 (b) 1500 (c) 1300
  30. 30.Best estimate of 20 × 54? (a) 1000 (b) 100 (c) 10000
  31. 31.Best estimate of 295 + 280? (a) 800 (b) 600 (c) 400
  32. 32.Best estimate of 63 × 27? (a) 180 (b) 18000 (c) 1800
  33. 33.Best estimate of 44 × 83? (a) 32000 (b) 320 (c) 3200
  34. 34.Best estimate of 67 × 31? (a) 21000 (b) 2100 (c) 210
  35. 35.Best estimate of 253 + 871? (a) 1400 (b) 1000 (c) 1200
  36. 36.Best estimate of 84 × 41? (a) 32000 (b) 320 (c) 3200
  37. 37.Best estimate of 72 × 50? (a) 35000 (b) 3500 (c) 350
  38. 38.Best estimate of 66 × 43? (a) 280 (b) 28000 (c) 2800
  39. 39.Best estimate of 68 × 27? (a) 2100 (b) 210 (c) 21000
  40. 40.Best estimate of 91 × 58? (a) 540 (b) 5400 (c) 54000

Answer key

  1. 900
  2. 1200
  3. 1500
  4. 1300
  5. 1300
  6. 300
  7. 4200
  8. 3200
  9. 7000
  10. 5600
  11. 1500
  12. 2400
  13. 3000
  14. 600
  15. 3600
  16. 3500
  17. 1800
  18. 1300
  19. 3600
  20. 8000
  21. 1100
  22. 3200
  23. 800
  24. 1300
  25. 2100
  26. 1200
  27. 1800
  28. 1100
  29. 1300
  30. 1000
  31. 600
  32. 1800
  33. 3200
  34. 2100
  35. 1200
  36. 3200
  37. 3500
  38. 2800
  39. 2100
  40. 5400

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