← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 991 · 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 50 × 81? (a) 40000 (b) 400 (c) 4000
  2. 2.Best estimate of 24 × 16? (a) 40 (b) 4000 (c) 400
  3. 3.Best estimate of 64 × 96? (a) 60000 (b) 6000 (c) 600
  4. 4.Best estimate of 202 + 820? (a) 1200 (b) 800 (c) 1000
  5. 5.Best estimate of 243 + 303? (a) 500 (b) 700 (c) 300
  6. 6.Best estimate of 222 + 181? (a) 200 (b) 600 (c) 400
  7. 7.Best estimate of 59 × 24? (a) 12000 (b) 120 (c) 1200
  8. 8.Best estimate of 602 + 739? (a) 1500 (b) 1100 (c) 1300
  9. 9.Best estimate of 396 + 271? (a) 700 (b) 500 (c) 900
  10. 10.Best estimate of 48 × 14? (a) 500 (b) 50 (c) 5000
  11. 11.Best estimate of 27 × 78? (a) 2400 (b) 240 (c) 24000
  12. 12.Best estimate of 158 + 423? (a) 800 (b) 400 (c) 600
  13. 13.Best estimate of 51 × 30? (a) 15000 (b) 1500 (c) 150
  14. 14.Best estimate of 616 + 308? (a) 1100 (b) 900 (c) 700
  15. 15.Best estimate of 96 × 41? (a) 4000 (b) 400 (c) 40000
  16. 16.Best estimate of 43 × 36? (a) 1600 (b) 16000 (c) 160
  17. 17.Best estimate of 19 × 39? (a) 800 (b) 8000 (c) 80
  18. 18.Best estimate of 62 × 34? (a) 18000 (b) 1800 (c) 180
  19. 19.Best estimate of 745 + 202? (a) 1100 (b) 900 (c) 700
  20. 20.Best estimate of 570 + 858? (a) 1500 (b) 1300 (c) 1700
  21. 21.Best estimate of 479 + 586? (a) 1100 (b) 1300 (c) 900
  22. 22.Best estimate of 79 × 64? (a) 4800 (b) 480 (c) 48000
  23. 23.Best estimate of 60 × 51? (a) 30000 (b) 300 (c) 3000
  24. 24.Best estimate of 856 + 812? (a) 1900 (b) 1500 (c) 1700
  25. 25.Best estimate of 84 × 81? (a) 6400 (b) 640 (c) 64000
  26. 26.Best estimate of 42 × 22? (a) 800 (b) 8000 (c) 80
  27. 27.Best estimate of 87 × 47? (a) 4500 (b) 450 (c) 45000
  28. 28.Best estimate of 548 + 483? (a) 1000 (b) 800 (c) 1200
  29. 29.Best estimate of 89 × 88? (a) 8100 (b) 81000 (c) 810
  30. 30.Best estimate of 21 × 56? (a) 12000 (b) 1200 (c) 120
  31. 31.Best estimate of 20 × 60? (a) 12000 (b) 1200 (c) 120
  32. 32.Best estimate of 828 + 716? (a) 1700 (b) 1300 (c) 1500
  33. 33.Best estimate of 739 + 551? (a) 1500 (b) 1100 (c) 1300
  34. 34.Best estimate of 76 × 51? (a) 4000 (b) 400 (c) 40000
  35. 35.Best estimate of 54 × 70? (a) 35000 (b) 3500 (c) 350
  36. 36.Best estimate of 200 + 215? (a) 400 (b) 600 (c) 200
  37. 37.Best estimate of 60 × 40? (a) 24000 (b) 240 (c) 2400
  38. 38.Best estimate of 630 + 559? (a) 1000 (b) 1200 (c) 1400
  39. 39.Best estimate of 97 × 66? (a) 70000 (b) 7000 (c) 700
  40. 40.Best estimate of 137 + 836? (a) 1100 (b) 700 (c) 900

Answer key

  1. 4000
  2. 400
  3. 6000
  4. 1000
  5. 500
  6. 400
  7. 1200
  8. 1300
  9. 700
  10. 500
  11. 2400
  12. 600
  13. 1500
  14. 900
  15. 4000
  16. 1600
  17. 800
  18. 1800
  19. 900
  20. 1500
  21. 1100
  22. 4800
  23. 3000
  24. 1700
  25. 6400
  26. 800
  27. 4500
  28. 1000
  29. 8100
  30. 1200
  31. 1200
  32. 1500
  33. 1300
  34. 4000
  35. 3500
  36. 400
  37. 2400
  38. 1200
  39. 7000
  40. 900

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