← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 786 · 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 770 + 434? (a) 1400 (b) 1000 (c) 1200
  2. 2.Best estimate of 26 × 24? (a) 600 (b) 6000 (c) 60
  3. 3.Best estimate of 594 + 155? (a) 600 (b) 800 (c) 1000
  4. 4.Best estimate of 78 × 42? (a) 3200 (b) 320 (c) 32000
  5. 5.Best estimate of 54 × 96? (a) 50000 (b) 5000 (c) 500
  6. 6.Best estimate of 27 × 52? (a) 15000 (b) 1500 (c) 150
  7. 7.Best estimate of 27 × 66? (a) 2100 (b) 21000 (c) 210
  8. 8.Best estimate of 56 × 63? (a) 360 (b) 3600 (c) 36000
  9. 9.Best estimate of 17 × 19? (a) 40 (b) 4000 (c) 400
  10. 10.Best estimate of 24 × 29? (a) 60 (b) 600 (c) 6000
  11. 11.Best estimate of 93 × 72? (a) 63000 (b) 6300 (c) 630
  12. 12.Best estimate of 761 + 151? (a) 1200 (b) 1000 (c) 800
  13. 13.Best estimate of 44 × 32? (a) 120 (b) 1200 (c) 12000
  14. 14.Best estimate of 38 × 72? (a) 2800 (b) 28000 (c) 280
  15. 15.Best estimate of 30 × 48? (a) 150 (b) 1500 (c) 15000
  16. 16.Best estimate of 525 + 742? (a) 1000 (b) 1400 (c) 1200
  17. 17.Best estimate of 317 + 585? (a) 900 (b) 700 (c) 1100
  18. 18.Best estimate of 185 + 686? (a) 700 (b) 1100 (c) 900
  19. 19.Best estimate of 46 × 61? (a) 30000 (b) 300 (c) 3000
  20. 20.Best estimate of 390 + 467? (a) 700 (b) 900 (c) 1100
  21. 21.Best estimate of 79 × 81? (a) 6400 (b) 64000 (c) 640
  22. 22.Best estimate of 58 × 14? (a) 6000 (b) 60 (c) 600
  23. 23.Best estimate of 226 + 492? (a) 500 (b) 900 (c) 700
  24. 24.Best estimate of 50 × 74? (a) 35000 (b) 350 (c) 3500
  25. 25.Best estimate of 56 × 33? (a) 18000 (b) 180 (c) 1800
  26. 26.Best estimate of 46 × 70? (a) 3500 (b) 35000 (c) 350
  27. 27.Best estimate of 26 × 26? (a) 9000 (b) 900 (c) 90
  28. 28.Best estimate of 632 + 247? (a) 1000 (b) 600 (c) 800
  29. 29.Best estimate of 44 × 50? (a) 200 (b) 2000 (c) 20000
  30. 30.Best estimate of 37 × 67? (a) 28000 (b) 280 (c) 2800
  31. 31.Best estimate of 707 + 381? (a) 1100 (b) 900 (c) 1300
  32. 32.Best estimate of 399 + 799? (a) 1200 (b) 1400 (c) 1000
  33. 33.Best estimate of 451 + 535? (a) 800 (b) 1000 (c) 1200
  34. 34.Best estimate of 89 × 37? (a) 3600 (b) 36000 (c) 360
  35. 35.Best estimate of 457 + 126? (a) 600 (b) 400 (c) 800
  36. 36.Best estimate of 44 × 90? (a) 36000 (b) 3600 (c) 360
  37. 37.Best estimate of 90 × 73? (a) 6300 (b) 63000 (c) 630
  38. 38.Best estimate of 643 + 256? (a) 900 (b) 1100 (c) 700
  39. 39.Best estimate of 820 + 679? (a) 1300 (b) 1500 (c) 1700
  40. 40.Best estimate of 71 × 78? (a) 5600 (b) 560 (c) 56000

Answer key

  1. 1200
  2. 600
  3. 800
  4. 3200
  5. 5000
  6. 1500
  7. 2100
  8. 3600
  9. 400
  10. 600
  11. 6300
  12. 1000
  13. 1200
  14. 2800
  15. 1500
  16. 1200
  17. 900
  18. 900
  19. 3000
  20. 900
  21. 6400
  22. 600
  23. 700
  24. 3500
  25. 1800
  26. 3500
  27. 900
  28. 800
  29. 2000
  30. 2800
  31. 1100
  32. 1200
  33. 1000
  34. 3600
  35. 600
  36. 3600
  37. 6300
  38. 900
  39. 1500
  40. 5600

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