← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 730 · 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.Best estimate of 3949 ÷ 56? (a) 66 (b) 6600 (c) 660
  2. 2.Best estimate of 1621 ÷ 57? (a) 270 (b) 2700 (c) 27
  3. 3.Best estimate of 8017 ÷ 89? (a) 89 (b) 890 (c) 8900
  4. 4.√32 to 1 decimal place? (a) 5.8 (b) 5.7 (c) 5.5 (d) 5.6
  5. 5.Best estimate of 2972 ÷ 86? (a) 330 (b) 33 (c) 3300
  6. 6.Best estimate of 1022 ÷ 81? (a) 130 (b) 1300 (c) 13
  7. 7.Best estimate of 2754 ÷ 46? (a) 5500 (b) 550 (c) 55
  8. 8.√79 to 1 decimal place? (a) 9.1 (b) 9.0 (c) 8.9 (d) 9.2
  9. 9.Best estimate of 805 ÷ 29? (a) 2700 (b) 27 (c) 270
  10. 10.Best estimate of 1274 ÷ 47? (a) 2500 (b) 25 (c) 250
  11. 11.Best estimate of 2915 ÷ 56? (a) 49 (b) 490 (c) 4900
  12. 12.Best estimate of 1111 ÷ 46? (a) 2200 (b) 220 (c) 22
  13. 13.√43 to 1 decimal place? (a) 6.5 (b) 6.4 (c) 6.6 (d) 6.3
  14. 14.Best estimate of 1726 ÷ 74? (a) 2500 (b) 25 (c) 250
  15. 15.Best estimate of 4434 ÷ 62? (a) 7400 (b) 740 (c) 74
  16. 16.√59 to 1 decimal place? (a) 7.9 (b) 8.0 (c) 7.8 (d) 7.7
  17. 17.√58 to 1 decimal place? (a) 7.7 (b) 7.6 (c) 7.4 (d) 7.5
  18. 18.√22 to 1 decimal place? (a) 4.7 (b) 4.4 (c) 4.5 (d) 4.6
  19. 19.Best estimate of 574 ÷ 31? (a) 190 (b) 19 (c) 1900
  20. 20.√40 to 1 decimal place? (a) 6.2 (b) 6.0 (c) 6.1 (d) 6.3
  21. 21.Best estimate of 1517 ÷ 28? (a) 5100 (b) 510 (c) 51
  22. 22.Best estimate of 1823 ÷ 26? (a) 61 (b) 610 (c) 6100
  23. 23.Best estimate of 1065 ÷ 27? (a) 36 (b) 3600 (c) 360
  24. 24.Best estimate of 952 ÷ 32? (a) 3200 (b) 32 (c) 320
  25. 25.√87 to 1 decimal place? (a) 9.4 (b) 9.3 (c) 9.5 (d) 9.6
  26. 26.Best estimate of 1219 ÷ 71? (a) 17 (b) 1700 (c) 170
  27. 27.√61 to 1 decimal place? (a) 7.9 (b) 7.8 (c) 8.0 (d) 7.7
  28. 28.Best estimate of 615 ÷ 51? (a) 120 (b) 1200 (c) 12
  29. 29.Best estimate of 654 ÷ 33? (a) 220 (b) 22 (c) 2200
  30. 30.Best estimate of 1699 ÷ 59? (a) 28 (b) 280 (c) 2800
  31. 31.√67 to 1 decimal place? (a) 8.2 (b) 8.3 (c) 8.1 (d) 8.0
  32. 32.Best estimate of 7522 ÷ 79? (a) 94 (b) 940 (c) 9400
  33. 33.Best estimate of 6696 ÷ 82? (a) 84 (b) 8400 (c) 840
  34. 34.Best estimate of 1910 ÷ 23? (a) 9600 (b) 960 (c) 96
  35. 35.Best estimate of 2311 ÷ 62? (a) 3900 (b) 39 (c) 390
  36. 36.√85 to 1 decimal place? (a) 9.2 (b) 9.4 (c) 9.3 (d) 9.5
  37. 37.Best estimate of 6239 ÷ 73? (a) 890 (b) 89 (c) 8900
  38. 38.Best estimate of 3098 ÷ 57? (a) 5200 (b) 52 (c) 520
  39. 39.Best estimate of 2955 ÷ 72? (a) 4200 (b) 42 (c) 420
  40. 40.√55 to 1 decimal place? (a) 7.2 (b) 7.3 (c) 7.4 (d) 7.1

Answer key

  1. 66
  2. 27
  3. 89
  4. 5.7
  5. 33
  6. 13
  7. 55
  8. 8.9
  9. 27
  10. 25
  11. 49
  12. 22
  13. 6.6
  14. 25
  15. 74
  16. 7.7
  17. 7.6
  18. 4.7
  19. 19
  20. 6.3
  21. 51
  22. 61
  23. 36
  24. 32
  25. 9.3
  26. 17
  27. 7.8
  28. 12
  29. 22
  30. 28
  31. 8.2
  32. 94
  33. 84
  34. 96
  35. 39
  36. 9.2
  37. 89
  38. 52
  39. 42
  40. 7.4

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