← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 882 · 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 752 + 280? (a) 1300 (b) 1100 (c) 900
  2. 2.Best estimate of 29 × 17? (a) 6000 (b) 60 (c) 600
  3. 3.Best estimate of 12 × 14? (a) 100 (b) 1000 (c) 10
  4. 4.Best estimate of 822 + 366? (a) 1200 (b) 1000 (c) 1400
  5. 5.Best estimate of 495 + 526? (a) 1200 (b) 800 (c) 1000
  6. 6.Best estimate of 44 × 53? (a) 20000 (b) 200 (c) 2000
  7. 7.Best estimate of 27 × 90? (a) 2700 (b) 27000 (c) 270
  8. 8.Best estimate of 168 + 427? (a) 800 (b) 600 (c) 400
  9. 9.Best estimate of 54 × 79? (a) 400 (b) 4000 (c) 40000
  10. 10.Best estimate of 224 + 296? (a) 700 (b) 300 (c) 500
  11. 11.Best estimate of 46 × 53? (a) 250 (b) 2500 (c) 25000
  12. 12.Best estimate of 422 + 201? (a) 800 (b) 400 (c) 600
  13. 13.Best estimate of 86 × 83? (a) 720 (b) 72000 (c) 7200
  14. 14.Best estimate of 27 × 16? (a) 60 (b) 6000 (c) 600
  15. 15.Best estimate of 862 + 465? (a) 1200 (b) 1600 (c) 1400
  16. 16.Best estimate of 832 + 517? (a) 1500 (b) 1300 (c) 1100
  17. 17.Best estimate of 691 + 722? (a) 1400 (b) 1600 (c) 1200
  18. 18.Best estimate of 47 × 36? (a) 2000 (b) 20000 (c) 200
  19. 19.Best estimate of 542 + 768? (a) 1300 (b) 1100 (c) 1500
  20. 20.Best estimate of 146 + 463? (a) 600 (b) 800 (c) 400
  21. 21.Best estimate of 407 + 232? (a) 800 (b) 400 (c) 600
  22. 22.Best estimate of 28 × 83? (a) 240 (b) 2400 (c) 24000
  23. 23.Best estimate of 601 + 123? (a) 500 (b) 700 (c) 900
  24. 24.Best estimate of 641 + 428? (a) 1000 (b) 1200 (c) 800
  25. 25.Best estimate of 36 × 30? (a) 12000 (b) 1200 (c) 120
  26. 26.Best estimate of 559 + 787? (a) 1200 (b) 1400 (c) 1600
  27. 27.Best estimate of 271 + 554? (a) 700 (b) 900 (c) 1100
  28. 28.Best estimate of 77 × 42? (a) 32000 (b) 320 (c) 3200
  29. 29.Best estimate of 349 + 233? (a) 300 (b) 500 (c) 700
  30. 30.Best estimate of 71 × 31? (a) 21000 (b) 210 (c) 2100
  31. 31.Best estimate of 79 × 70? (a) 560 (b) 56000 (c) 5600
  32. 32.Best estimate of 434 + 285? (a) 900 (b) 700 (c) 500
  33. 33.Best estimate of 652 + 202? (a) 900 (b) 1100 (c) 700
  34. 34.Best estimate of 38 × 69? (a) 28000 (b) 280 (c) 2800
  35. 35.Best estimate of 56 × 73? (a) 420 (b) 4200 (c) 42000
  36. 36.Best estimate of 543 + 455? (a) 1000 (b) 800 (c) 1200
  37. 37.Best estimate of 47 × 46? (a) 250 (b) 25000 (c) 2500
  38. 38.Best estimate of 67 × 87? (a) 6300 (b) 63000 (c) 630
  39. 39.Best estimate of 14 × 68? (a) 700 (b) 70 (c) 7000
  40. 40.Best estimate of 92 × 66? (a) 63000 (b) 6300 (c) 630

Answer key

  1. 1100
  2. 600
  3. 100
  4. 1200
  5. 1000
  6. 2000
  7. 2700
  8. 600
  9. 4000
  10. 500
  11. 2500
  12. 600
  13. 7200
  14. 600
  15. 1400
  16. 1300
  17. 1400
  18. 2000
  19. 1300
  20. 600
  21. 600
  22. 2400
  23. 700
  24. 1000
  25. 1200
  26. 1400
  27. 900
  28. 3200
  29. 500
  30. 2100
  31. 5600
  32. 700
  33. 900
  34. 2800
  35. 4200
  36. 1000
  37. 2500
  38. 6300
  39. 700
  40. 6300

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