← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 706 · 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 2830 ÷ 67? (a) 400 (b) 4000 (c) 40
  2. 2.Best estimate of 4072 ÷ 66? (a) 580 (b) 58 (c) 5800
  3. 3.Best estimate of 584 ÷ 46? (a) 120 (b) 12 (c) 1200
  4. 4.Best estimate of 4999 ÷ 56? (a) 830 (b) 8300 (c) 83
  5. 5.√55 to 1 decimal place? (a) 7.2 (b) 7.4 (c) 7.1 (d) 7.3
  6. 6.Best estimate of 975 ÷ 36? (a) 240 (b) 24 (c) 2400
  7. 7.√89 to 1 decimal place? (a) 9.1 (b) 9.3 (c) 9.2 (d) 9.4
  8. 8.√56 to 1 decimal place? (a) 7.4 (b) 7.6 (c) 7.5 (d) 7.3
  9. 9.√69 to 1 decimal place? (a) 8.3 (b) 8.2 (c) 8.5 (d) 8.4
  10. 10.Best estimate of 1398 ÷ 31? (a) 470 (b) 47 (c) 4700
  11. 11.√75 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.4 (d) 8.7
  12. 12.Best estimate of 2737 ÷ 69? (a) 390 (b) 3900 (c) 39
  13. 13.Best estimate of 975 ÷ 57? (a) 1600 (b) 16 (c) 160
  14. 14.Best estimate of 2588 ÷ 42? (a) 650 (b) 65 (c) 6500
  15. 15.√98 to 1 decimal place? (a) 9.8 (b) 9.7 (c) 9.9 (d) 10.0
  16. 16.Best estimate of 2895 ÷ 56? (a) 480 (b) 4800 (c) 48
  17. 17.Best estimate of 7032 ÷ 78? (a) 880 (b) 88 (c) 8800
  18. 18.Best estimate of 1848 ÷ 36? (a) 460 (b) 46 (c) 4600
  19. 19.√78 to 1 decimal place? (a) 8.6 (b) 8.7 (c) 8.9 (d) 8.8
  20. 20.Best estimate of 1356 ÷ 32? (a) 4500 (b) 45 (c) 450
  21. 21.√37 to 1 decimal place? (a) 5.9 (b) 6.2 (c) 6.1 (d) 6.0
  22. 22.Best estimate of 2261 ÷ 64? (a) 38 (b) 380 (c) 3800
  23. 23.Best estimate of 4744 ÷ 72? (a) 68 (b) 680 (c) 6800
  24. 24.√96 to 1 decimal place? (a) 9.6 (b) 9.7 (c) 9.9 (d) 9.8
  25. 25.Best estimate of 749 ÷ 39? (a) 190 (b) 19 (c) 1900
  26. 26.Best estimate of 5648 ÷ 67? (a) 810 (b) 81 (c) 8100
  27. 27.Best estimate of 485 ÷ 33? (a) 1600 (b) 16 (c) 160
  28. 28.Best estimate of 1814 ÷ 56? (a) 300 (b) 3000 (c) 30
  29. 29.√38 to 1 decimal place? (a) 6.3 (b) 6.2 (c) 6.4 (d) 6.1
  30. 30.Best estimate of 1142 ÷ 38? (a) 290 (b) 2900 (c) 29
  31. 31.Best estimate of 4431 ÷ 79? (a) 550 (b) 5500 (c) 55
  32. 32.Best estimate of 2788 ÷ 32? (a) 930 (b) 9300 (c) 93
  33. 33.Best estimate of 1994 ÷ 62? (a) 33 (b) 3300 (c) 330
  34. 34.√82 to 1 decimal place? (a) 9.2 (b) 9.3 (c) 9.0 (d) 9.1
  35. 35.Best estimate of 2237 ÷ 46? (a) 45 (b) 4500 (c) 450
  36. 36.√74 to 1 decimal place? (a) 8.8 (b) 8.7 (c) 8.9 (d) 8.6
  37. 37.√40 to 1 decimal place? (a) 6.5 (b) 6.6 (c) 6.3 (d) 6.4
  38. 38.Best estimate of 2376 ÷ 41? (a) 59 (b) 590 (c) 5900
  39. 39.Best estimate of 6159 ÷ 76? (a) 77 (b) 7700 (c) 770
  40. 40.Best estimate of 760 ÷ 56? (a) 130 (b) 1300 (c) 13

Answer key

  1. 40
  2. 58
  3. 12
  4. 83
  5. 7.4
  6. 24
  7. 9.4
  8. 7.5
  9. 8.3
  10. 47
  11. 8.7
  12. 39
  13. 16
  14. 65
  15. 9.9
  16. 48
  17. 88
  18. 46
  19. 8.8
  20. 45
  21. 6.1
  22. 38
  23. 68
  24. 9.8
  25. 19
  26. 81
  27. 16
  28. 30
  29. 6.2
  30. 29
  31. 55
  32. 93
  33. 33
  34. 9.1
  35. 45
  36. 8.6
  37. 6.3
  38. 59
  39. 77
  40. 13

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