← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 1 · 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 19 × 71? (a) 1400 (b) 14000 (c) 140
  2. 2.Best estimate of 97 × 48? (a) 50000 (b) 5000 (c) 500
  3. 3.Best estimate of 77 × 84? (a) 6400 (b) 640 (c) 64000
  4. 4.Best estimate of 695 + 835? (a) 1700 (b) 1500 (c) 1300
  5. 5.Best estimate of 753 + 478? (a) 1300 (b) 1500 (c) 1100
  6. 6.Best estimate of 352 + 735? (a) 1300 (b) 1100 (c) 900
  7. 7.Best estimate of 14 × 56? (a) 60 (b) 6000 (c) 600
  8. 8.Best estimate of 59 × 23? (a) 120 (b) 1200 (c) 12000
  9. 9.Best estimate of 155 + 653? (a) 700 (b) 1100 (c) 900
  10. 10.Best estimate of 16 × 54? (a) 100 (b) 10000 (c) 1000
  11. 11.Best estimate of 365 + 603? (a) 1000 (b) 800 (c) 1200
  12. 12.Best estimate of 292 + 430? (a) 500 (b) 700 (c) 900
  13. 13.Best estimate of 301 + 475? (a) 600 (b) 1000 (c) 800
  14. 14.Best estimate of 500 + 727? (a) 1400 (b) 1200 (c) 1000
  15. 15.Best estimate of 86 × 38? (a) 3600 (b) 36000 (c) 360
  16. 16.Best estimate of 38 × 50? (a) 2000 (b) 200 (c) 20000
  17. 17.Best estimate of 741 + 799? (a) 1700 (b) 1300 (c) 1500
  18. 18.Best estimate of 58 × 23? (a) 1200 (b) 120 (c) 12000
  19. 19.Best estimate of 274 + 347? (a) 400 (b) 800 (c) 600
  20. 20.Best estimate of 66 × 83? (a) 5600 (b) 560 (c) 56000
  21. 21.Best estimate of 309 + 537? (a) 600 (b) 1000 (c) 800
  22. 22.Best estimate of 569 + 757? (a) 1400 (b) 1600 (c) 1200
  23. 23.Best estimate of 167 + 284? (a) 700 (b) 300 (c) 500
  24. 24.Best estimate of 367 + 588? (a) 1000 (b) 800 (c) 1200
  25. 25.Best estimate of 325 + 574? (a) 1100 (b) 700 (c) 900
  26. 26.Best estimate of 56 × 86? (a) 54000 (b) 540 (c) 5400
  27. 27.Best estimate of 156 + 698? (a) 1100 (b) 900 (c) 700
  28. 28.Best estimate of 19 × 57? (a) 12000 (b) 1200 (c) 120
  29. 29.Best estimate of 243 + 273? (a) 500 (b) 700 (c) 300
  30. 30.Best estimate of 664 + 171? (a) 1100 (b) 900 (c) 700
  31. 31.Best estimate of 26 × 74? (a) 2100 (b) 21000 (c) 210
  32. 32.Best estimate of 66 × 19? (a) 1400 (b) 140 (c) 14000
  33. 33.Best estimate of 86 × 30? (a) 2700 (b) 27000 (c) 270
  34. 34.Best estimate of 622 + 309? (a) 1100 (b) 700 (c) 900
  35. 35.Best estimate of 79 × 14? (a) 800 (b) 80 (c) 8000
  36. 36.Best estimate of 61 × 30? (a) 180 (b) 18000 (c) 1800
  37. 37.Best estimate of 68 × 54? (a) 350 (b) 3500 (c) 35000
  38. 38.Best estimate of 46 × 97? (a) 5000 (b) 50000 (c) 500
  39. 39.Best estimate of 218 + 322? (a) 700 (b) 300 (c) 500
  40. 40.Best estimate of 369 + 396? (a) 1000 (b) 800 (c) 600

Answer key

  1. 1400
  2. 5000
  3. 6400
  4. 1500
  5. 1300
  6. 1100
  7. 600
  8. 1200
  9. 900
  10. 1000
  11. 1000
  12. 700
  13. 800
  14. 1200
  15. 3600
  16. 2000
  17. 1500
  18. 1200
  19. 600
  20. 5600
  21. 800
  22. 1400
  23. 500
  24. 1000
  25. 900
  26. 5400
  27. 900
  28. 1200
  29. 500
  30. 900
  31. 2100
  32. 1400
  33. 2700
  34. 900
  35. 800
  36. 1800
  37. 3500
  38. 5000
  39. 500
  40. 800

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