← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 264 · 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 36 × 39? (a) 1600 (b) 160 (c) 16000
  2. 2.Best estimate of 179 + 584? (a) 800 (b) 1000 (c) 600
  3. 3.Best estimate of 245 + 563? (a) 1000 (b) 600 (c) 800
  4. 4.Best estimate of 390 + 153? (a) 600 (b) 400 (c) 800
  5. 5.Best estimate of 865 + 390? (a) 1100 (b) 1300 (c) 1500
  6. 6.Best estimate of 67 × 30? (a) 2100 (b) 210 (c) 21000
  7. 7.Best estimate of 67 × 33? (a) 2100 (b) 21000 (c) 210
  8. 8.Best estimate of 46 × 96? (a) 50000 (b) 500 (c) 5000
  9. 9.Best estimate of 70 × 26? (a) 2100 (b) 210 (c) 21000
  10. 10.Best estimate of 14 × 44? (a) 400 (b) 40 (c) 4000
  11. 11.Best estimate of 292 + 767? (a) 1300 (b) 900 (c) 1100
  12. 12.Best estimate of 37 × 46? (a) 20000 (b) 2000 (c) 200
  13. 13.Best estimate of 291 + 205? (a) 700 (b) 300 (c) 500
  14. 14.Best estimate of 472 + 489? (a) 1200 (b) 800 (c) 1000
  15. 15.Best estimate of 584 + 433? (a) 1200 (b) 800 (c) 1000
  16. 16.Best estimate of 663 + 428? (a) 900 (b) 1300 (c) 1100
  17. 17.Best estimate of 744 + 707? (a) 1400 (b) 1200 (c) 1600
  18. 18.Best estimate of 57 × 12? (a) 6000 (b) 600 (c) 60
  19. 19.Best estimate of 737 + 239? (a) 700 (b) 1100 (c) 900
  20. 20.Best estimate of 70 × 62? (a) 42000 (b) 420 (c) 4200
  21. 21.Best estimate of 82 × 50? (a) 400 (b) 4000 (c) 40000
  22. 22.Best estimate of 518 + 392? (a) 1100 (b) 700 (c) 900
  23. 23.Best estimate of 19 × 46? (a) 10000 (b) 1000 (c) 100
  24. 24.Best estimate of 33 × 36? (a) 120 (b) 1200 (c) 12000
  25. 25.Best estimate of 261 + 181? (a) 500 (b) 300 (c) 700
  26. 26.Best estimate of 664 + 686? (a) 1400 (b) 1200 (c) 1600
  27. 27.Best estimate of 36 × 57? (a) 24000 (b) 2400 (c) 240
  28. 28.Best estimate of 96 × 91? (a) 900 (b) 9000 (c) 90000
  29. 29.Best estimate of 226 + 172? (a) 600 (b) 200 (c) 400
  30. 30.Best estimate of 273 + 491? (a) 800 (b) 600 (c) 1000
  31. 31.Best estimate of 536 + 781? (a) 1500 (b) 1100 (c) 1300
  32. 32.Best estimate of 47 × 86? (a) 450 (b) 45000 (c) 4500
  33. 33.Best estimate of 34 × 52? (a) 150 (b) 1500 (c) 15000
  34. 34.Best estimate of 804 + 194? (a) 1200 (b) 800 (c) 1000
  35. 35.Best estimate of 724 + 746? (a) 1400 (b) 1200 (c) 1600
  36. 36.Best estimate of 62 × 64? (a) 360 (b) 36000 (c) 3600
  37. 37.Best estimate of 158 + 325? (a) 300 (b) 700 (c) 500
  38. 38.Best estimate of 286 + 219? (a) 300 (b) 700 (c) 500
  39. 39.Best estimate of 310 + 700? (a) 1200 (b) 800 (c) 1000
  40. 40.Best estimate of 464 + 241? (a) 500 (b) 900 (c) 700

Answer key

  1. 1600
  2. 800
  3. 800
  4. 600
  5. 1300
  6. 2100
  7. 2100
  8. 5000
  9. 2100
  10. 400
  11. 1100
  12. 2000
  13. 500
  14. 1000
  15. 1000
  16. 1100
  17. 1400
  18. 600
  19. 900
  20. 4200
  21. 4000
  22. 900
  23. 1000
  24. 1200
  25. 500
  26. 1400
  27. 2400
  28. 9000
  29. 400
  30. 800
  31. 1300
  32. 4500
  33. 1500
  34. 1000
  35. 1400
  36. 3600
  37. 500
  38. 500
  39. 1000
  40. 700

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