← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 363 · 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 96 × 18? (a) 20000 (b) 200 (c) 2000
  2. 2.Best estimate of 529 + 151? (a) 700 (b) 500 (c) 900
  3. 3.Best estimate of 80 × 62? (a) 48000 (b) 480 (c) 4800
  4. 4.Best estimate of 337 + 351? (a) 700 (b) 500 (c) 900
  5. 5.Best estimate of 861 + 399? (a) 1500 (b) 1300 (c) 1100
  6. 6.Best estimate of 677 + 844? (a) 1700 (b) 1300 (c) 1500
  7. 7.Best estimate of 58 × 16? (a) 12000 (b) 120 (c) 1200
  8. 8.Best estimate of 412 + 351? (a) 1000 (b) 600 (c) 800
  9. 9.Best estimate of 451 + 555? (a) 900 (b) 1300 (c) 1100
  10. 10.Best estimate of 556 + 144? (a) 700 (b) 900 (c) 500
  11. 11.Best estimate of 589 + 159? (a) 800 (b) 600 (c) 1000
  12. 12.Best estimate of 46 × 74? (a) 3500 (b) 350 (c) 35000
  13. 13.Best estimate of 24 × 30? (a) 6000 (b) 600 (c) 60
  14. 14.Best estimate of 86 × 39? (a) 3600 (b) 360 (c) 36000
  15. 15.Best estimate of 683 + 813? (a) 1300 (b) 1500 (c) 1700
  16. 16.Best estimate of 126 + 309? (a) 400 (b) 600 (c) 200
  17. 17.Best estimate of 47 × 24? (a) 100 (b) 1000 (c) 10000
  18. 18.Best estimate of 680 + 561? (a) 1500 (b) 1100 (c) 1300
  19. 19.Best estimate of 790 + 406? (a) 1000 (b) 1200 (c) 1400
  20. 20.Best estimate of 460 + 237? (a) 500 (b) 900 (c) 700
  21. 21.Best estimate of 749 + 322? (a) 800 (b) 1000 (c) 1200
  22. 22.Best estimate of 14 × 72? (a) 70 (b) 700 (c) 7000
  23. 23.Best estimate of 17 × 90? (a) 1800 (b) 18000 (c) 180
  24. 24.Best estimate of 52 × 72? (a) 350 (b) 3500 (c) 35000
  25. 25.Best estimate of 74 × 33? (a) 210 (b) 21000 (c) 2100
  26. 26.Best estimate of 738 + 851? (a) 1600 (b) 1800 (c) 1400
  27. 27.Best estimate of 76 × 71? (a) 56000 (b) 560 (c) 5600
  28. 28.Best estimate of 565 + 274? (a) 1100 (b) 700 (c) 900
  29. 29.Best estimate of 60 × 20? (a) 1200 (b) 12000 (c) 120
  30. 30.Best estimate of 34 × 79? (a) 2400 (b) 24000 (c) 240
  31. 31.Best estimate of 16 × 21? (a) 400 (b) 4000 (c) 40
  32. 32.Best estimate of 685 + 761? (a) 1300 (b) 1500 (c) 1700
  33. 33.Best estimate of 29 × 90? (a) 27000 (b) 270 (c) 2700
  34. 34.Best estimate of 86 × 88? (a) 81000 (b) 810 (c) 8100
  35. 35.Best estimate of 33 × 82? (a) 2400 (b) 24000 (c) 240
  36. 36.Best estimate of 38 × 57? (a) 24000 (b) 2400 (c) 240
  37. 37.Best estimate of 68 × 68? (a) 4900 (b) 490 (c) 49000
  38. 38.Best estimate of 42 × 12? (a) 400 (b) 40 (c) 4000
  39. 39.Best estimate of 633 + 678? (a) 1300 (b) 1500 (c) 1100
  40. 40.Best estimate of 97 × 60? (a) 60000 (b) 6000 (c) 600

Answer key

  1. 2000
  2. 700
  3. 4800
  4. 700
  5. 1300
  6. 1500
  7. 1200
  8. 800
  9. 1100
  10. 700
  11. 800
  12. 3500
  13. 600
  14. 3600
  15. 1500
  16. 400
  17. 1000
  18. 1300
  19. 1200
  20. 700
  21. 1000
  22. 700
  23. 1800
  24. 3500
  25. 2100
  26. 1600
  27. 5600
  28. 900
  29. 1200
  30. 2400
  31. 400
  32. 1500
  33. 2700
  34. 8100
  35. 2400
  36. 2400
  37. 4900
  38. 400
  39. 1300
  40. 6000

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