← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 955 · 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 46 × 21? (a) 10000 (b) 100 (c) 1000
  2. 2.Best estimate of 22 × 78? (a) 1600 (b) 16000 (c) 160
  3. 3.Best estimate of 876 + 608? (a) 1700 (b) 1500 (c) 1300
  4. 4.Best estimate of 33 × 94? (a) 27000 (b) 2700 (c) 270
  5. 5.Best estimate of 22 × 68? (a) 14000 (b) 140 (c) 1400
  6. 6.Best estimate of 376 + 841? (a) 1200 (b) 1000 (c) 1400
  7. 7.Best estimate of 13 × 56? (a) 60 (b) 6000 (c) 600
  8. 8.Best estimate of 852 + 296? (a) 1000 (b) 1200 (c) 1400
  9. 9.Best estimate of 856 + 703? (a) 1600 (b) 1400 (c) 1800
  10. 10.Best estimate of 374 + 843? (a) 1200 (b) 1000 (c) 1400
  11. 11.Best estimate of 82 × 86? (a) 720 (b) 7200 (c) 72000
  12. 12.Best estimate of 96 × 67? (a) 7000 (b) 70000 (c) 700
  13. 13.Best estimate of 878 + 653? (a) 1600 (b) 1400 (c) 1800
  14. 14.Best estimate of 853 + 530? (a) 1400 (b) 1200 (c) 1600
  15. 15.Best estimate of 29 × 58? (a) 1800 (b) 18000 (c) 180
  16. 16.Best estimate of 94 × 17? (a) 1800 (b) 180 (c) 18000
  17. 17.Best estimate of 46 × 81? (a) 400 (b) 4000 (c) 40000
  18. 18.Best estimate of 64 × 29? (a) 180 (b) 1800 (c) 18000
  19. 19.Best estimate of 345 + 600? (a) 900 (b) 1100 (c) 700
  20. 20.Best estimate of 206 + 271? (a) 300 (b) 500 (c) 700
  21. 21.Best estimate of 582 + 340? (a) 900 (b) 1100 (c) 700
  22. 22.Best estimate of 26 × 96? (a) 3000 (b) 30000 (c) 300
  23. 23.Best estimate of 73 × 93? (a) 630 (b) 63000 (c) 6300
  24. 24.Best estimate of 33 × 72? (a) 2100 (b) 21000 (c) 210
  25. 25.Best estimate of 371 + 635? (a) 800 (b) 1000 (c) 1200
  26. 26.Best estimate of 90 × 76? (a) 720 (b) 7200 (c) 72000
  27. 27.Best estimate of 361 + 251? (a) 700 (b) 900 (c) 500
  28. 28.Best estimate of 23 × 42? (a) 80 (b) 8000 (c) 800
  29. 29.Best estimate of 853 + 878? (a) 1800 (b) 2000 (c) 1600
  30. 30.Best estimate of 41 × 56? (a) 240 (b) 24000 (c) 2400
  31. 31.Best estimate of 197 + 267? (a) 500 (b) 700 (c) 300
  32. 32.Best estimate of 49 × 59? (a) 30000 (b) 300 (c) 3000
  33. 33.Best estimate of 73 × 12? (a) 70 (b) 700 (c) 7000
  34. 34.Best estimate of 156 + 541? (a) 700 (b) 900 (c) 500
  35. 35.Best estimate of 59 × 96? (a) 6000 (b) 600 (c) 60000
  36. 36.Best estimate of 52 × 72? (a) 3500 (b) 35000 (c) 350
  37. 37.Best estimate of 148 + 205? (a) 100 (b) 300 (c) 500
  38. 38.Best estimate of 32 × 39? (a) 12000 (b) 120 (c) 1200
  39. 39.Best estimate of 770 + 629? (a) 1200 (b) 1400 (c) 1600
  40. 40.Best estimate of 50 × 21? (a) 10000 (b) 100 (c) 1000

Answer key

  1. 1000
  2. 1600
  3. 1500
  4. 2700
  5. 1400
  6. 1200
  7. 600
  8. 1200
  9. 1600
  10. 1200
  11. 7200
  12. 7000
  13. 1600
  14. 1400
  15. 1800
  16. 1800
  17. 4000
  18. 1800
  19. 900
  20. 500
  21. 900
  22. 3000
  23. 6300
  24. 2100
  25. 1000
  26. 7200
  27. 700
  28. 800
  29. 1800
  30. 2400
  31. 500
  32. 3000
  33. 700
  34. 700
  35. 6000
  36. 3500
  37. 300
  38. 1200
  39. 1400
  40. 1000

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