← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 469 · 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 97 × 24? (a) 2000 (b) 20000 (c) 200
  2. 2.Best estimate of 68 × 34? (a) 210 (b) 21000 (c) 2100
  3. 3.Best estimate of 31 × 31? (a) 900 (b) 9000 (c) 90
  4. 4.Best estimate of 78 × 36? (a) 320 (b) 32000 (c) 3200
  5. 5.Best estimate of 43 × 17? (a) 8000 (b) 800 (c) 80
  6. 6.Best estimate of 93 × 37? (a) 3600 (b) 36000 (c) 360
  7. 7.Best estimate of 31 × 73? (a) 21000 (b) 2100 (c) 210
  8. 8.Best estimate of 263 + 417? (a) 500 (b) 700 (c) 900
  9. 9.Best estimate of 86 × 49? (a) 45000 (b) 4500 (c) 450
  10. 10.Best estimate of 28 × 81? (a) 240 (b) 2400 (c) 24000
  11. 11.Best estimate of 80 × 48? (a) 400 (b) 40000 (c) 4000
  12. 12.Best estimate of 741 + 626? (a) 1100 (b) 1500 (c) 1300
  13. 13.Best estimate of 86 × 60? (a) 5400 (b) 540 (c) 54000
  14. 14.Best estimate of 300 + 165? (a) 300 (b) 500 (c) 700
  15. 15.Best estimate of 96 × 19? (a) 20000 (b) 200 (c) 2000
  16. 16.Best estimate of 839 + 298? (a) 1100 (b) 900 (c) 1300
  17. 17.Best estimate of 597 + 240? (a) 1000 (b) 800 (c) 600
  18. 18.Best estimate of 18 × 24? (a) 4000 (b) 40 (c) 400
  19. 19.Best estimate of 23 × 64? (a) 120 (b) 12000 (c) 1200
  20. 20.Best estimate of 628 + 213? (a) 1000 (b) 600 (c) 800
  21. 21.Best estimate of 47 × 76? (a) 40000 (b) 4000 (c) 400
  22. 22.Best estimate of 257 + 310? (a) 800 (b) 600 (c) 400
  23. 23.Best estimate of 392 + 431? (a) 1000 (b) 800 (c) 600
  24. 24.Best estimate of 756 + 652? (a) 1500 (b) 1300 (c) 1700
  25. 25.Best estimate of 22 × 80? (a) 160 (b) 1600 (c) 16000
  26. 26.Best estimate of 82 × 76? (a) 640 (b) 64000 (c) 6400
  27. 27.Best estimate of 12 × 84? (a) 8000 (b) 800 (c) 80
  28. 28.Best estimate of 26 × 98? (a) 30000 (b) 300 (c) 3000
  29. 29.Best estimate of 27 × 74? (a) 21000 (b) 2100 (c) 210
  30. 30.Best estimate of 26 × 76? (a) 240 (b) 24000 (c) 2400
  31. 31.Best estimate of 89 × 81? (a) 7200 (b) 72000 (c) 720
  32. 32.Best estimate of 92 × 17? (a) 180 (b) 18000 (c) 1800
  33. 33.Best estimate of 21 × 31? (a) 60 (b) 600 (c) 6000
  34. 34.Best estimate of 187 + 422? (a) 600 (b) 800 (c) 400
  35. 35.Best estimate of 41 × 49? (a) 200 (b) 20000 (c) 2000
  36. 36.Best estimate of 87 × 52? (a) 4500 (b) 450 (c) 45000
  37. 37.Best estimate of 96 × 54? (a) 500 (b) 50000 (c) 5000
  38. 38.Best estimate of 92 × 78? (a) 72000 (b) 7200 (c) 720
  39. 39.Best estimate of 222 + 695? (a) 1100 (b) 900 (c) 700
  40. 40.Best estimate of 89 × 84? (a) 72000 (b) 7200 (c) 720

Answer key

  1. 2000
  2. 2100
  3. 900
  4. 3200
  5. 800
  6. 3600
  7. 2100
  8. 700
  9. 4500
  10. 2400
  11. 4000
  12. 1300
  13. 5400
  14. 500
  15. 2000
  16. 1100
  17. 800
  18. 400
  19. 1200
  20. 800
  21. 4000
  22. 600
  23. 800
  24. 1500
  25. 1600
  26. 6400
  27. 800
  28. 3000
  29. 2100
  30. 2400
  31. 7200
  32. 1800
  33. 600
  34. 600
  35. 2000
  36. 4500
  37. 5000
  38. 7200
  39. 900
  40. 7200

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