← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 137 · 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 6097 ÷ 81? (a) 7600 (b) 760 (c) 76
  2. 2.√48 to 1 decimal place? (a) 6.9 (b) 7.0 (c) 7.2 (d) 7.1
  3. 3.Best estimate of 1292 ÷ 36? (a) 32 (b) 3200 (c) 320
  4. 4.Best estimate of 6888 ÷ 72? (a) 980 (b) 9800 (c) 98
  5. 5.Best estimate of 4232 ÷ 66? (a) 600 (b) 6000 (c) 60
  6. 6.√66 to 1 decimal place? (a) 8.0 (b) 8.1 (c) 7.9 (d) 8.2
  7. 7.Best estimate of 957 ÷ 42? (a) 24 (b) 2400 (c) 240
  8. 8.Best estimate of 2654 ÷ 51? (a) 5300 (b) 530 (c) 53
  9. 9.Best estimate of 1442 ÷ 73? (a) 2100 (b) 21 (c) 210
  10. 10.Best estimate of 3051 ÷ 37? (a) 760 (b) 7600 (c) 76
  11. 11.√92 to 1 decimal place? (a) 9.8 (b) 9.5 (c) 9.7 (d) 9.6
  12. 12.√26 to 1 decimal place? (a) 5.1 (b) 5.0 (c) 5.2 (d) 4.9
  13. 13.Best estimate of 2137 ÷ 26? (a) 710 (b) 7100 (c) 71
  14. 14.√27 to 1 decimal place? (a) 5.4 (b) 5.2 (c) 5.3 (d) 5.5
  15. 15.√41 to 1 decimal place? (a) 6.6 (b) 6.7 (c) 6.4 (d) 6.5
  16. 16.√30 to 1 decimal place? (a) 5.8 (b) 5.6 (c) 5.7 (d) 5.5
  17. 17.√98 to 1 decimal place? (a) 9.9 (b) 9.8 (c) 9.6 (d) 9.7
  18. 18.Best estimate of 4593 ÷ 69? (a) 660 (b) 6600 (c) 66
  19. 19.Best estimate of 6330 ÷ 66? (a) 9000 (b) 900 (c) 90
  20. 20.Best estimate of 2612 ÷ 28? (a) 8700 (b) 870 (c) 87
  21. 21.√53 to 1 decimal place? (a) 7.2 (b) 7.4 (c) 7.1 (d) 7.3
  22. 22.√29 to 1 decimal place? (a) 5.7 (b) 5.6 (c) 5.5 (d) 5.4
  23. 23.Best estimate of 4293 ÷ 47? (a) 86 (b) 860 (c) 8600
  24. 24.√84 to 1 decimal place? (a) 9.5 (b) 9.3 (c) 9.2 (d) 9.4
  25. 25.√35 to 1 decimal place? (a) 6.0 (b) 6.1 (c) 5.9 (d) 6.2
  26. 26.Best estimate of 7648 ÷ 83? (a) 960 (b) 9600 (c) 96
  27. 27.Best estimate of 2402 ÷ 38? (a) 600 (b) 6000 (c) 60
  28. 28.Best estimate of 2538 ÷ 58? (a) 420 (b) 42 (c) 4200
  29. 29.Best estimate of 1117 ÷ 69? (a) 160 (b) 1600 (c) 16
  30. 30.√65 to 1 decimal place? (a) 7.8 (b) 7.9 (c) 8.0 (d) 8.1
  31. 31.√40 to 1 decimal place? (a) 6.5 (b) 6.4 (c) 6.3 (d) 6.2
  32. 32.Best estimate of 4685 ÷ 88? (a) 5200 (b) 520 (c) 52
  33. 33.Best estimate of 1842 ÷ 46? (a) 370 (b) 3700 (c) 37
  34. 34.Best estimate of 2839 ÷ 34? (a) 9500 (b) 95 (c) 950
  35. 35.√74 to 1 decimal place? (a) 8.8 (b) 8.7 (c) 8.9 (d) 8.6
  36. 36.√55 to 1 decimal place? (a) 7.4 (b) 7.6 (c) 7.3 (d) 7.5
  37. 37.√38 to 1 decimal place? (a) 6.0 (b) 6.1 (c) 6.2 (d) 5.9
  38. 38.√78 to 1 decimal place? (a) 8.6 (b) 8.9 (c) 8.7 (d) 8.8
  39. 39.Best estimate of 5771 ÷ 62? (a) 9600 (b) 960 (c) 96
  40. 40.Best estimate of 1101 ÷ 88? (a) 1200 (b) 12 (c) 120

Answer key

  1. 76
  2. 6.9
  3. 32
  4. 98
  5. 60
  6. 8.1
  7. 24
  8. 53
  9. 21
  10. 76
  11. 9.6
  12. 5.1
  13. 71
  14. 5.2
  15. 6.4
  16. 5.5
  17. 9.9
  18. 66
  19. 90
  20. 87
  21. 7.3
  22. 5.4
  23. 86
  24. 9.2
  25. 5.9
  26. 96
  27. 60
  28. 42
  29. 16
  30. 8.1
  31. 6.3
  32. 52
  33. 37
  34. 95
  35. 8.6
  36. 7.4
  37. 6.2
  38. 8.8
  39. 96
  40. 12

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