← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 283 · 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 3186 ÷ 76? (a) 40 (b) 4000 (c) 400
  2. 2.Best estimate of 5005 ÷ 82? (a) 6300 (b) 63 (c) 630
  3. 3.√26 to 1 decimal place? (a) 5.0 (b) 5.1 (c) 4.9 (d) 4.8
  4. 4.√52 to 1 decimal place? (a) 7.2 (b) 7.3 (c) 7.4 (d) 7.1
  5. 5.Best estimate of 3402 ÷ 41? (a) 85 (b) 8500 (c) 850
  6. 6.Best estimate of 1417 ÷ 22? (a) 7100 (b) 71 (c) 710
  7. 7.√37 to 1 decimal place? (a) 5.9 (b) 6.2 (c) 6.1 (d) 6.0
  8. 8.Best estimate of 2933 ÷ 86? (a) 33 (b) 330 (c) 3300
  9. 9.√66 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 7.8 (d) 8.0
  10. 10.Best estimate of 4384 ÷ 63? (a) 7300 (b) 730 (c) 73
  11. 11.Best estimate of 806 ÷ 22? (a) 400 (b) 40 (c) 4000
  12. 12.√79 to 1 decimal place? (a) 8.9 (b) 9.1 (c) 9.0 (d) 9.2
  13. 13.Best estimate of 846 ÷ 32? (a) 28 (b) 2800 (c) 280
  14. 14.√61 to 1 decimal place? (a) 7.5 (b) 7.6 (c) 7.7 (d) 7.8
  15. 15.Best estimate of 3677 ÷ 67? (a) 530 (b) 5300 (c) 53
  16. 16.√41 to 1 decimal place? (a) 6.3 (b) 6.2 (c) 6.5 (d) 6.4
  17. 17.√58 to 1 decimal place? (a) 7.8 (b) 7.9 (c) 7.7 (d) 7.6
  18. 18.Best estimate of 1964 ÷ 72? (a) 2800 (b) 280 (c) 28
  19. 19.√32 to 1 decimal place? (a) 6.0 (b) 5.7 (c) 5.8 (d) 5.9
  20. 20.Best estimate of 2442 ÷ 26? (a) 81 (b) 8100 (c) 810
  21. 21.√70 to 1 decimal place? (a) 8.3 (b) 8.5 (c) 8.6 (d) 8.4
  22. 22.Best estimate of 760 ÷ 29? (a) 25 (b) 250 (c) 2500
  23. 23.Best estimate of 1101 ÷ 38? (a) 2800 (b) 28 (c) 280
  24. 24.Best estimate of 726 ÷ 32? (a) 240 (b) 2400 (c) 24
  25. 25.√34 to 1 decimal place? (a) 6.0 (b) 5.8 (c) 5.9 (d) 5.7
  26. 26.Best estimate of 3476 ÷ 69? (a) 50 (b) 5000 (c) 500
  27. 27.√27 to 1 decimal place? (a) 5.3 (b) 5.4 (c) 5.2 (d) 5.5
  28. 28.√69 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.5 (d) 8.2
  29. 29.√87 to 1 decimal place? (a) 9.3 (b) 9.2 (c) 9.0 (d) 9.1
  30. 30.Best estimate of 2300 ÷ 38? (a) 5800 (b) 58 (c) 580
  31. 31.√42 to 1 decimal place? (a) 6.5 (b) 6.6 (c) 6.8 (d) 6.7
  32. 32.Best estimate of 1339 ÷ 27? (a) 45 (b) 450 (c) 4500
  33. 33.Best estimate of 2193 ÷ 38? (a) 55 (b) 5500 (c) 550
  34. 34.√74 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.5 (d) 8.6
  35. 35.√21 to 1 decimal place? (a) 4.8 (b) 4.5 (c) 4.6 (d) 4.7
  36. 36.√29 to 1 decimal place? (a) 5.2 (b) 5.4 (c) 5.1 (d) 5.3
  37. 37.Best estimate of 837 ÷ 42? (a) 21 (b) 2100 (c) 210
  38. 38.Best estimate of 2508 ÷ 48? (a) 50 (b) 500 (c) 5000
  39. 39.Best estimate of 2695 ÷ 76? (a) 340 (b) 3400 (c) 34
  40. 40.Best estimate of 7494 ÷ 79? (a) 94 (b) 9400 (c) 940

Answer key

  1. 40
  2. 63
  3. 5.1
  4. 7.2
  5. 85
  6. 71
  7. 6.1
  8. 33
  9. 8.1
  10. 73
  11. 40
  12. 8.9
  13. 28
  14. 7.8
  15. 53
  16. 6.4
  17. 7.6
  18. 28
  19. 5.7
  20. 81
  21. 8.4
  22. 25
  23. 28
  24. 24
  25. 5.8
  26. 50
  27. 5.2
  28. 8.3
  29. 9.3
  30. 58
  31. 6.5
  32. 45
  33. 55
  34. 8.6
  35. 4.6
  36. 5.4
  37. 21
  38. 50
  39. 34
  40. 94

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