← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 452 · 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 5992 ÷ 83? (a) 750 (b) 75 (c) 7500
  2. 2.Best estimate of 2142 ÷ 32? (a) 71 (b) 710 (c) 7100
  3. 3.√71 to 1 decimal place? (a) 8.4 (b) 8.7 (c) 8.6 (d) 8.5
  4. 4.√29 to 1 decimal place? (a) 5.4 (b) 5.5 (c) 5.6 (d) 5.7
  5. 5.Best estimate of 1441 ÷ 58? (a) 240 (b) 24 (c) 2400
  6. 6.Best estimate of 1259 ÷ 26? (a) 420 (b) 4200 (c) 42
  7. 7.√43 to 1 decimal place? (a) 6.3 (b) 6.6 (c) 6.5 (d) 6.4
  8. 8.Best estimate of 4275 ÷ 88? (a) 480 (b) 4800 (c) 48
  9. 9.√38 to 1 decimal place? (a) 6.4 (b) 6.3 (c) 6.1 (d) 6.2
  10. 10.Best estimate of 6634 ÷ 86? (a) 74 (b) 740 (c) 7400
  11. 11.Best estimate of 3727 ÷ 48? (a) 750 (b) 7500 (c) 75
  12. 12.√65 to 1 decimal place? (a) 8.0 (b) 7.9 (c) 7.8 (d) 8.1
  13. 13.√23 to 1 decimal place? (a) 4.9 (b) 4.8 (c) 4.7 (d) 5.0
  14. 14.Best estimate of 1063 ÷ 32? (a) 35 (b) 350 (c) 3500
  15. 15.Best estimate of 6925 ÷ 88? (a) 77 (b) 7700 (c) 770
  16. 16.√27 to 1 decimal place? (a) 5.3 (b) 5.1 (c) 5.0 (d) 5.2
  17. 17.Best estimate of 1657 ÷ 32? (a) 5500 (b) 550 (c) 55
  18. 18.Best estimate of 1775 ÷ 26? (a) 5900 (b) 590 (c) 59
  19. 19.Best estimate of 2741 ÷ 72? (a) 39 (b) 390 (c) 3900
  20. 20.√74 to 1 decimal place? (a) 8.7 (b) 8.5 (c) 8.6 (d) 8.4
  21. 21.√96 to 1 decimal place? (a) 10.0 (b) 9.8 (c) 9.7 (d) 9.9
  22. 22.√83 to 1 decimal place? (a) 9.1 (b) 8.8 (c) 8.9 (d) 9.0
  23. 23.√21 to 1 decimal place? (a) 4.8 (b) 4.6 (c) 4.7 (d) 4.5
  24. 24.Best estimate of 844 ÷ 28? (a) 280 (b) 2800 (c) 28
  25. 25.Best estimate of 2399 ÷ 34? (a) 800 (b) 8000 (c) 80
  26. 26.√52 to 1 decimal place? (a) 7.1 (b) 7.3 (c) 7.0 (d) 7.2
  27. 27.√34 to 1 decimal place? (a) 6.0 (b) 5.8 (c) 5.7 (d) 5.9
  28. 28.Best estimate of 1258 ÷ 38? (a) 3100 (b) 31 (c) 310
  29. 29.√92 to 1 decimal place? (a) 9.6 (b) 9.5 (c) 9.7 (d) 9.8
  30. 30.√87 to 1 decimal place? (a) 9.0 (b) 9.3 (c) 9.2 (d) 9.1
  31. 31.Best estimate of 4669 ÷ 82? (a) 5800 (b) 58 (c) 580
  32. 32.Best estimate of 4933 ÷ 82? (a) 620 (b) 6200 (c) 62
  33. 33.Best estimate of 3845 ÷ 87? (a) 43 (b) 430 (c) 4300
  34. 34.Best estimate of 6700 ÷ 72? (a) 960 (b) 96 (c) 9600
  35. 35.√82 to 1 decimal place? (a) 9.4 (b) 9.3 (c) 9.1 (d) 9.2
  36. 36.Best estimate of 1279 ÷ 36? (a) 3200 (b) 320 (c) 32
  37. 37.Best estimate of 1112 ÷ 44? (a) 2800 (b) 280 (c) 28
  38. 38.Best estimate of 457 ÷ 34? (a) 1500 (b) 15 (c) 150
  39. 39.Best estimate of 4130 ÷ 67? (a) 5900 (b) 59 (c) 590
  40. 40.Best estimate of 1128 ÷ 31? (a) 380 (b) 3800 (c) 38

Answer key

  1. 75
  2. 71
  3. 8.4
  4. 5.4
  5. 24
  6. 42
  7. 6.6
  8. 48
  9. 6.2
  10. 74
  11. 75
  12. 8.1
  13. 4.8
  14. 35
  15. 77
  16. 5.2
  17. 55
  18. 59
  19. 39
  20. 8.6
  21. 9.8
  22. 9.1
  23. 4.6
  24. 28
  25. 80
  26. 7.2
  27. 5.8
  28. 31
  29. 9.6
  30. 9.3
  31. 58
  32. 62
  33. 43
  34. 96
  35. 9.1
  36. 32
  37. 28
  38. 15
  39. 59
  40. 38

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