← Rounding off and best estimate lesson New set →

Rounding Off and Estimation Worksheet

Mental maths lesson 15: Rounding off and best estimate · Set 857 · 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 701 + 509? (a) 1200 (b) 1400 (c) 1000
  2. 2.Best estimate of 79 × 34? (a) 240 (b) 24000 (c) 2400
  3. 3.Best estimate of 83 × 93? (a) 7200 (b) 72000 (c) 720
  4. 4.Best estimate of 625 + 579? (a) 1200 (b) 1000 (c) 1400
  5. 5.Best estimate of 79 × 21? (a) 16000 (b) 160 (c) 1600
  6. 6.Best estimate of 649 + 170? (a) 600 (b) 800 (c) 1000
  7. 7.Best estimate of 47 × 36? (a) 200 (b) 20000 (c) 2000
  8. 8.Best estimate of 243 + 866? (a) 1300 (b) 1100 (c) 900
  9. 9.Best estimate of 56 × 88? (a) 540 (b) 54000 (c) 5400
  10. 10.Best estimate of 214 + 639? (a) 600 (b) 800 (c) 1000
  11. 11.Best estimate of 18 × 30? (a) 6000 (b) 600 (c) 60
  12. 12.Best estimate of 649 + 544? (a) 900 (b) 1100 (c) 1300
  13. 13.Best estimate of 53 × 36? (a) 2000 (b) 200 (c) 20000
  14. 14.Best estimate of 30 × 78? (a) 240 (b) 24000 (c) 2400
  15. 15.Best estimate of 23 × 38? (a) 80 (b) 8000 (c) 800
  16. 16.Best estimate of 27 × 62? (a) 1800 (b) 18000 (c) 180
  17. 17.Best estimate of 22 × 37? (a) 80 (b) 800 (c) 8000
  18. 18.Best estimate of 23 × 86? (a) 1800 (b) 18000 (c) 180
  19. 19.Best estimate of 40 × 74? (a) 28000 (b) 2800 (c) 280
  20. 20.Best estimate of 64 × 96? (a) 600 (b) 60000 (c) 6000
  21. 21.Best estimate of 98 × 87? (a) 9000 (b) 90000 (c) 900
  22. 22.Best estimate of 241 + 206? (a) 400 (b) 600 (c) 200
  23. 23.Best estimate of 353 + 290? (a) 900 (b) 500 (c) 700
  24. 24.Best estimate of 732 + 511? (a) 1000 (b) 1400 (c) 1200
  25. 25.Best estimate of 605 + 722? (a) 1100 (b) 1300 (c) 1500
  26. 26.Best estimate of 73 × 42? (a) 2800 (b) 28000 (c) 280
  27. 27.Best estimate of 70 × 70? (a) 490 (b) 49000 (c) 4900
  28. 28.Best estimate of 374 + 520? (a) 900 (b) 1100 (c) 700
  29. 29.Best estimate of 66 × 47? (a) 3500 (b) 35000 (c) 350
  30. 30.Best estimate of 413 + 519? (a) 1100 (b) 700 (c) 900
  31. 31.Best estimate of 80 × 54? (a) 4000 (b) 400 (c) 40000
  32. 32.Best estimate of 89 × 67? (a) 63000 (b) 630 (c) 6300
  33. 33.Best estimate of 14 × 96? (a) 10000 (b) 100 (c) 1000
  34. 34.Best estimate of 274 + 592? (a) 900 (b) 1100 (c) 700
  35. 35.Best estimate of 304 + 218? (a) 300 (b) 700 (c) 500
  36. 36.Best estimate of 78 × 36? (a) 32000 (b) 320 (c) 3200
  37. 37.Best estimate of 36 × 57? (a) 240 (b) 24000 (c) 2400
  38. 38.Best estimate of 46 × 52? (a) 2500 (b) 25000 (c) 250
  39. 39.Best estimate of 36 × 67? (a) 280 (b) 2800 (c) 28000
  40. 40.Best estimate of 246 + 248? (a) 600 (b) 400 (c) 200

Answer key

  1. 1200
  2. 2400
  3. 7200
  4. 1200
  5. 1600
  6. 800
  7. 2000
  8. 1100
  9. 5400
  10. 800
  11. 600
  12. 1100
  13. 2000
  14. 2400
  15. 800
  16. 1800
  17. 800
  18. 1800
  19. 2800
  20. 6000
  21. 9000
  22. 400
  23. 700
  24. 1200
  25. 1300
  26. 2800
  27. 4900
  28. 900
  29. 3500
  30. 900
  31. 4000
  32. 6300
  33. 1000
  34. 900
  35. 500
  36. 3200
  37. 2400
  38. 2500
  39. 2800
  40. 400

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