← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 72 · 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.√37 to 1 decimal place? (a) 6.1 (b) 6.3 (c) 6.0 (d) 6.2
  2. 2.√21 to 1 decimal place? (a) 4.7 (b) 4.8 (c) 4.6 (d) 4.9
  3. 3.√80 to 1 decimal place? (a) 8.9 (b) 8.6 (c) 8.8 (d) 8.7
  4. 4.Best estimate of 584 ÷ 26? (a) 190 (b) 19 (c) 1900
  5. 5.Best estimate of 1568 ÷ 39? (a) 390 (b) 3900 (c) 39
  6. 6.Best estimate of 929 ÷ 44? (a) 23 (b) 2300 (c) 230
  7. 7.√30 to 1 decimal place? (a) 5.6 (b) 5.5 (c) 5.4 (d) 5.3
  8. 8.Best estimate of 2383 ÷ 57? (a) 40 (b) 4000 (c) 400
  9. 9.Best estimate of 1130 ÷ 26? (a) 380 (b) 38 (c) 3800
  10. 10.√38 to 1 decimal place? (a) 6.2 (b) 6.3 (c) 6.1 (d) 6.4
  11. 11.√43 to 1 decimal place? (a) 6.7 (b) 6.5 (c) 6.6 (d) 6.4
  12. 12.√40 to 1 decimal place? (a) 6.3 (b) 6.2 (c) 6.0 (d) 6.1
  13. 13.Best estimate of 657 ÷ 27? (a) 220 (b) 2200 (c) 22
  14. 14.Best estimate of 3847 ÷ 72? (a) 55 (b) 5500 (c) 550
  15. 15.Best estimate of 4943 ÷ 62? (a) 8200 (b) 82 (c) 820
  16. 16.√61 to 1 decimal place? (a) 7.8 (b) 8.0 (c) 8.1 (d) 7.9
  17. 17.Best estimate of 1029 ÷ 33? (a) 3400 (b) 340 (c) 34
  18. 18.√27 to 1 decimal place? (a) 5.0 (b) 4.9 (c) 5.1 (d) 5.2
  19. 19.√65 to 1 decimal place? (a) 8.2 (b) 8.0 (c) 8.3 (d) 8.1
  20. 20.√70 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.4 (d) 8.3
  21. 21.Best estimate of 2575 ÷ 68? (a) 370 (b) 37 (c) 3700
  22. 22.Best estimate of 1026 ÷ 38? (a) 26 (b) 2600 (c) 260
  23. 23.Best estimate of 1591 ÷ 22? (a) 8000 (b) 80 (c) 800
  24. 24.√26 to 1 decimal place? (a) 5.1 (b) 5.2 (c) 5.3 (d) 5.4
  25. 25.Best estimate of 5056 ÷ 61? (a) 8400 (b) 840 (c) 84
  26. 26.Best estimate of 4228 ÷ 58? (a) 7000 (b) 70 (c) 700
  27. 27.Best estimate of 5253 ÷ 56? (a) 880 (b) 8800 (c) 88
  28. 28.Best estimate of 2102 ÷ 23? (a) 1050 (b) 10500 (c) 105
  29. 29.Best estimate of 1235 ÷ 58? (a) 210 (b) 2100 (c) 21
  30. 30.Best estimate of 2358 ÷ 42? (a) 5900 (b) 59 (c) 590
  31. 31.√55 to 1 decimal place? (a) 7.2 (b) 7.3 (c) 7.1 (d) 7.4
  32. 32.Best estimate of 2919 ÷ 68? (a) 42 (b) 4200 (c) 420
  33. 33.Best estimate of 701 ÷ 23? (a) 3500 (b) 35 (c) 350
  34. 34.Best estimate of 2391 ÷ 27? (a) 800 (b) 8000 (c) 80
  35. 35.Best estimate of 1794 ÷ 74? (a) 260 (b) 26 (c) 2600
  36. 36.√28 to 1 decimal place? (a) 5.2 (b) 5.4 (c) 5.5 (d) 5.3
  37. 37.√58 to 1 decimal place? (a) 7.8 (b) 7.6 (c) 7.7 (d) 7.9
  38. 38.Best estimate of 959 ÷ 76? (a) 1200 (b) 120 (c) 12
  39. 39.Best estimate of 4157 ÷ 86? (a) 46 (b) 460 (c) 4600
  40. 40.Best estimate of 3341 ÷ 88? (a) 3700 (b) 37 (c) 370

Answer key

  1. 6.1
  2. 4.6
  3. 8.9
  4. 19
  5. 39
  6. 23
  7. 5.5
  8. 40
  9. 38
  10. 6.2
  11. 6.6
  12. 6.3
  13. 22
  14. 55
  15. 82
  16. 7.8
  17. 34
  18. 5.2
  19. 8.1
  20. 8.4
  21. 37
  22. 26
  23. 80
  24. 5.1
  25. 84
  26. 70
  27. 88
  28. 105
  29. 21
  30. 59
  31. 7.4
  32. 42
  33. 35
  34. 80
  35. 26
  36. 5.3
  37. 7.6
  38. 12
  39. 46
  40. 37

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