← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 560 · 40 questions
TalentJR

How to do it in your head (Guess, divide, average): Division: round the divisor to the nearest ten and find the closest multiple of it. Square root: guess the nearest whole root, then divide the number by your guess. Average the guess and the answer of the division, and round to 1 decimal place.

NameDateTime takenScore ___ / 40
  1. 1.√31 to 1 decimal place? (a) 5.7 (b) 5.8 (c) 5.5 (d) 5.6
  2. 2.Best estimate of 4326 ÷ 49? (a) 87 (b) 870 (c) 8700
  3. 3.Best estimate of 7490 ÷ 81? (a) 9400 (b) 940 (c) 94
  4. 4.√27 to 1 decimal place? (a) 5.2 (b) 5.1 (c) 5.3 (d) 5.0
  5. 5.Best estimate of 1023 ÷ 22? (a) 510 (b) 51 (c) 5100
  6. 6.Best estimate of 2711 ÷ 33? (a) 9000 (b) 90 (c) 900
  7. 7.√50 to 1 decimal place? (a) 7.0 (b) 7.3 (c) 7.2 (d) 7.1
  8. 8.√21 to 1 decimal place? (a) 4.6 (b) 4.4 (c) 4.5 (d) 4.3
  9. 9.√44 to 1 decimal place? (a) 6.4 (b) 6.3 (c) 6.5 (d) 6.6
  10. 10.√32 to 1 decimal place? (a) 5.7 (b) 5.9 (c) 6.0 (d) 5.8
  11. 11.Best estimate of 4020 ÷ 67? (a) 5700 (b) 57 (c) 570
  12. 12.√20 to 1 decimal place? (a) 4.7 (b) 4.5 (c) 4.8 (d) 4.6
  13. 13.Best estimate of 1219 ÷ 36? (a) 300 (b) 30 (c) 3000
  14. 14.√87 to 1 decimal place? (a) 9.4 (b) 9.2 (c) 9.3 (d) 9.5
  15. 15.√34 to 1 decimal place? (a) 5.8 (b) 5.7 (c) 5.5 (d) 5.6
  16. 16.Best estimate of 4444 ÷ 56? (a) 7400 (b) 740 (c) 74
  17. 17.Best estimate of 2520 ÷ 29? (a) 840 (b) 84 (c) 8400
  18. 18.√37 to 1 decimal place? (a) 5.8 (b) 5.9 (c) 6.0 (d) 6.1
  19. 19.Best estimate of 1904 ÷ 36? (a) 480 (b) 4800 (c) 48
  20. 20.√40 to 1 decimal place? (a) 6.4 (b) 6.6 (c) 6.5 (d) 6.3
  21. 21.Best estimate of 2022 ÷ 41? (a) 510 (b) 5100 (c) 51
  22. 22.√46 to 1 decimal place? (a) 7.1 (b) 6.8 (c) 6.9 (d) 7.0
  23. 23.Best estimate of 3723 ÷ 72? (a) 5300 (b) 53 (c) 530
  24. 24.Best estimate of 1851 ÷ 44? (a) 460 (b) 4600 (c) 46
  25. 25.Best estimate of 5604 ÷ 76? (a) 70 (b) 7000 (c) 700
  26. 26.√63 to 1 decimal place? (a) 8.1 (b) 8.0 (c) 7.9 (d) 7.8
  27. 27.Best estimate of 5026 ÷ 73? (a) 72 (b) 7200 (c) 720
  28. 28.Best estimate of 1764 ÷ 54? (a) 35 (b) 3500 (c) 350
  29. 29.Best estimate of 2609 ÷ 72? (a) 37 (b) 3700 (c) 370
  30. 30.Best estimate of 1152 ÷ 33? (a) 380 (b) 38 (c) 3800
  31. 31.Best estimate of 3373 ÷ 48? (a) 670 (b) 67 (c) 6700
  32. 32.√84 to 1 decimal place? (a) 9.3 (b) 9.4 (c) 9.5 (d) 9.2
  33. 33.Best estimate of 1603 ÷ 47? (a) 3200 (b) 320 (c) 32
  34. 34.√43 to 1 decimal place? (a) 6.4 (b) 6.7 (c) 6.5 (d) 6.6
  35. 35.√58 to 1 decimal place? (a) 7.6 (b) 7.7 (c) 7.9 (d) 7.8
  36. 36.√83 to 1 decimal place? (a) 9.1 (b) 9.3 (c) 9.0 (d) 9.2
  37. 37.√82 to 1 decimal place? (a) 8.9 (b) 9.2 (c) 9.0 (d) 9.1
  38. 38.Best estimate of 3578 ÷ 76? (a) 4500 (b) 45 (c) 450
  39. 39.Best estimate of 3655 ÷ 43? (a) 9100 (b) 910 (c) 91
  40. 40.√92 to 1 decimal place? (a) 9.6 (b) 9.4 (c) 9.5 (d) 9.7

Answer key

  1. 5.6
  2. 87
  3. 94
  4. 5.2
  5. 51
  6. 90
  7. 7.1
  8. 4.6
  9. 6.6
  10. 5.7
  11. 57
  12. 4.5
  13. 30
  14. 9.3
  15. 5.8
  16. 74
  17. 84
  18. 6.1
  19. 48
  20. 6.3
  21. 51
  22. 6.8
  23. 53
  24. 46
  25. 70
  26. 7.9
  27. 72
  28. 35
  29. 37
  30. 38
  31. 67
  32. 9.2
  33. 32
  34. 6.6
  35. 7.6
  36. 9.1
  37. 9.1
  38. 45
  39. 91
  40. 9.6

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