← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 167 · 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 5534 ÷ 86? (a) 6100 (b) 610 (c) 61
  2. 2.√55 to 1 decimal place? (a) 7.4 (b) 7.5 (c) 7.2 (d) 7.3
  3. 3.√77 to 1 decimal place? (a) 9.1 (b) 8.8 (c) 8.9 (d) 9.0
  4. 4.Best estimate of 3557 ÷ 66? (a) 51 (b) 510 (c) 5100
  5. 5.Best estimate of 3664 ÷ 69? (a) 52 (b) 5200 (c) 520
  6. 6.√32 to 1 decimal place? (a) 5.7 (b) 5.8 (c) 5.6 (d) 5.5
  7. 7.Best estimate of 1227 ÷ 36? (a) 3100 (b) 310 (c) 31
  8. 8.√75 to 1 decimal place? (a) 8.6 (b) 8.7 (c) 8.9 (d) 8.8
  9. 9.√56 to 1 decimal place? (a) 7.6 (b) 7.4 (c) 7.5 (d) 7.7
  10. 10.Best estimate of 545 ÷ 24? (a) 270 (b) 2700 (c) 27
  11. 11.Best estimate of 2345 ÷ 72? (a) 340 (b) 34 (c) 3400
  12. 12.Best estimate of 3303 ÷ 52? (a) 660 (b) 66 (c) 6600
  13. 13.Best estimate of 967 ÷ 72? (a) 1400 (b) 140 (c) 14
  14. 14.Best estimate of 575 ÷ 24? (a) 29 (b) 290 (c) 2900
  15. 15.Best estimate of 3788 ÷ 59? (a) 6300 (b) 630 (c) 63
  16. 16.√88 to 1 decimal place? (a) 9.7 (b) 9.5 (c) 9.6 (d) 9.4
  17. 17.√65 to 1 decimal place? (a) 8.1 (b) 8.4 (c) 8.2 (d) 8.3
  18. 18.Best estimate of 1115 ÷ 87? (a) 120 (b) 12 (c) 1200
  19. 19.Best estimate of 4047 ÷ 57? (a) 670 (b) 6700 (c) 67
  20. 20.Best estimate of 1122 ÷ 84? (a) 1400 (b) 140 (c) 14
  21. 21.√38 to 1 decimal place? (a) 6.1 (b) 6.0 (c) 5.9 (d) 6.2
  22. 22.Best estimate of 3242 ÷ 36? (a) 8100 (b) 810 (c) 81
  23. 23.Best estimate of 4370 ÷ 68? (a) 62 (b) 6200 (c) 620
  24. 24.√82 to 1 decimal place? (a) 9.0 (b) 8.8 (c) 9.1 (d) 8.9
  25. 25.√89 to 1 decimal place? (a) 9.4 (b) 9.3 (c) 9.1 (d) 9.2
  26. 26.Best estimate of 4854 ÷ 72? (a) 69 (b) 6900 (c) 690
  27. 27.Best estimate of 2167 ÷ 29? (a) 720 (b) 72 (c) 7200
  28. 28.Best estimate of 4468 ÷ 62? (a) 74 (b) 7400 (c) 740
  29. 29.√58 to 1 decimal place? (a) 7.9 (b) 7.8 (c) 7.7 (d) 7.6
  30. 30.Best estimate of 4804 ÷ 56? (a) 800 (b) 80 (c) 8000
  31. 31.√85 to 1 decimal place? (a) 9.1 (b) 9.2 (c) 9.0 (d) 8.9
  32. 32.√53 to 1 decimal place? (a) 7.1 (b) 7.0 (c) 7.2 (d) 7.3
  33. 33.Best estimate of 1411 ÷ 36? (a) 3500 (b) 35 (c) 350
  34. 34.Best estimate of 1471 ÷ 86? (a) 1600 (b) 16 (c) 160
  35. 35.Best estimate of 1299 ÷ 27? (a) 430 (b) 4300 (c) 43
  36. 36.Best estimate of 3334 ÷ 46? (a) 670 (b) 6700 (c) 67
  37. 37.√42 to 1 decimal place? (a) 6.7 (b) 6.5 (c) 6.6 (d) 6.8
  38. 38.Best estimate of 1976 ÷ 81? (a) 2500 (b) 25 (c) 250
  39. 39.√26 to 1 decimal place? (a) 5.1 (b) 5.0 (c) 5.3 (d) 5.2
  40. 40.√96 to 1 decimal place? (a) 9.6 (b) 9.7 (c) 9.8 (d) 9.5

Answer key

  1. 61
  2. 7.4
  3. 8.8
  4. 51
  5. 52
  6. 5.7
  7. 31
  8. 8.7
  9. 7.5
  10. 27
  11. 34
  12. 66
  13. 14
  14. 29
  15. 63
  16. 9.4
  17. 8.1
  18. 12
  19. 67
  20. 14
  21. 6.2
  22. 81
  23. 62
  24. 9.1
  25. 9.4
  26. 69
  27. 72
  28. 74
  29. 7.6
  30. 80
  31. 9.2
  32. 7.3
  33. 35
  34. 16
  35. 43
  36. 67
  37. 6.5
  38. 25
  39. 5.1
  40. 9.8

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