← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 961 · 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 90 × 33? (a) 27000 (b) 2700 (c) 270
  2. 2.Best estimate of 497 + 206? (a) 500 (b) 900 (c) 700
  3. 3.Best estimate of 23 × 87? (a) 180 (b) 1800 (c) 18000
  4. 4.Best estimate of 66 × 51? (a) 350 (b) 3500 (c) 35000
  5. 5.Best estimate of 136 + 841? (a) 900 (b) 1100 (c) 700
  6. 6.Best estimate of 34 × 30? (a) 900 (b) 90 (c) 9000
  7. 7.Best estimate of 191 + 433? (a) 800 (b) 400 (c) 600
  8. 8.Best estimate of 82 × 26? (a) 2400 (b) 240 (c) 24000
  9. 9.Best estimate of 255 + 389? (a) 700 (b) 500 (c) 900
  10. 10.Best estimate of 19 × 94? (a) 1800 (b) 180 (c) 18000
  11. 11.Best estimate of 46 × 76? (a) 4000 (b) 400 (c) 40000
  12. 12.Best estimate of 758 + 476? (a) 1100 (b) 1500 (c) 1300
  13. 13.Best estimate of 53 × 69? (a) 35000 (b) 350 (c) 3500
  14. 14.Best estimate of 82 × 24? (a) 160 (b) 1600 (c) 16000
  15. 15.Best estimate of 559 + 188? (a) 800 (b) 1000 (c) 600
  16. 16.Best estimate of 28 × 27? (a) 900 (b) 90 (c) 9000
  17. 17.Best estimate of 14 × 73? (a) 700 (b) 70 (c) 7000
  18. 18.Best estimate of 434 + 317? (a) 900 (b) 500 (c) 700
  19. 19.Best estimate of 14 × 20? (a) 20 (b) 2000 (c) 200
  20. 20.Best estimate of 410 + 359? (a) 600 (b) 1000 (c) 800
  21. 21.Best estimate of 499 + 227? (a) 500 (b) 900 (c) 700
  22. 22.Best estimate of 712 + 196? (a) 1100 (b) 700 (c) 900
  23. 23.Best estimate of 86 × 36? (a) 36000 (b) 360 (c) 3600
  24. 24.Best estimate of 66 × 30? (a) 2100 (b) 210 (c) 21000
  25. 25.Best estimate of 71 × 46? (a) 3500 (b) 35000 (c) 350
  26. 26.Best estimate of 82 × 27? (a) 24000 (b) 240 (c) 2400
  27. 27.Best estimate of 23 × 13? (a) 20 (b) 2000 (c) 200
  28. 28.Best estimate of 200 + 167? (a) 600 (b) 400 (c) 200
  29. 29.Best estimate of 128 + 487? (a) 800 (b) 600 (c) 400
  30. 30.Best estimate of 41 × 17? (a) 80 (b) 8000 (c) 800
  31. 31.Best estimate of 697 + 249? (a) 900 (b) 700 (c) 1100
  32. 32.Best estimate of 46 × 16? (a) 10000 (b) 100 (c) 1000
  33. 33.Best estimate of 532 + 342? (a) 1000 (b) 600 (c) 800
  34. 34.Best estimate of 19 × 43? (a) 800 (b) 80 (c) 8000
  35. 35.Best estimate of 37 × 61? (a) 24000 (b) 2400 (c) 240
  36. 36.Best estimate of 21 × 70? (a) 14000 (b) 1400 (c) 140
  37. 37.Best estimate of 189 + 633? (a) 800 (b) 1000 (c) 600
  38. 38.Best estimate of 81 × 84? (a) 640 (b) 64000 (c) 6400
  39. 39.Best estimate of 24 × 49? (a) 10000 (b) 100 (c) 1000
  40. 40.Best estimate of 96 × 60? (a) 6000 (b) 60000 (c) 600

Answer key

  1. 2700
  2. 700
  3. 1800
  4. 3500
  5. 900
  6. 900
  7. 600
  8. 2400
  9. 700
  10. 1800
  11. 4000
  12. 1300
  13. 3500
  14. 1600
  15. 800
  16. 900
  17. 700
  18. 700
  19. 200
  20. 800
  21. 700
  22. 900
  23. 3600
  24. 2100
  25. 3500
  26. 2400
  27. 200
  28. 400
  29. 600
  30. 800
  31. 900
  32. 1000
  33. 800
  34. 800
  35. 2400
  36. 1400
  37. 800
  38. 6400
  39. 1000
  40. 6000

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