← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 527 · 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.√44 to 1 decimal place? (a) 6.7 (b) 6.6 (c) 6.9 (d) 6.8
  2. 2.√40 to 1 decimal place? (a) 6.2 (b) 6.1 (c) 6.3 (d) 6.4
  3. 3.√96 to 1 decimal place? (a) 10.1 (b) 9.9 (c) 10.0 (d) 9.8
  4. 4.√69 to 1 decimal place? (a) 8.4 (b) 8.5 (c) 8.3 (d) 8.6
  5. 5.√35 to 1 decimal place? (a) 5.9 (b) 5.7 (c) 5.8 (d) 5.6
  6. 6.Best estimate of 4997 ÷ 77? (a) 6200 (b) 62 (c) 620
  7. 7.√61 to 1 decimal place? (a) 8.0 (b) 7.8 (c) 7.9 (d) 8.1
  8. 8.Best estimate of 1363 ÷ 42? (a) 340 (b) 34 (c) 3400
  9. 9.Best estimate of 3089 ÷ 69? (a) 440 (b) 4400 (c) 44
  10. 10.√31 to 1 decimal place? (a) 5.5 (b) 5.4 (c) 5.7 (d) 5.6
  11. 11.√41 to 1 decimal place? (a) 6.5 (b) 6.7 (c) 6.4 (d) 6.6
  12. 12.Best estimate of 4751 ÷ 53? (a) 950 (b) 9500 (c) 95
  13. 13.√53 to 1 decimal place? (a) 7.3 (b) 7.1 (c) 7.2 (d) 7.0
  14. 14.Best estimate of 2066 ÷ 32? (a) 69 (b) 690 (c) 6900
  15. 15.√24 to 1 decimal place? (a) 5.2 (b) 4.9 (c) 5.0 (d) 5.1
  16. 16.Best estimate of 4349 ÷ 59? (a) 720 (b) 72 (c) 7200
  17. 17.Best estimate of 1475 ÷ 77? (a) 18 (b) 180 (c) 1800
  18. 18.√28 to 1 decimal place? (a) 5.3 (b) 5.4 (c) 5.5 (d) 5.6
  19. 19.Best estimate of 1017 ÷ 32? (a) 34 (b) 340 (c) 3400
  20. 20.√72 to 1 decimal place? (a) 8.6 (b) 8.4 (c) 8.7 (d) 8.5
  21. 21.Best estimate of 3542 ÷ 38? (a) 890 (b) 8900 (c) 89
  22. 22.Best estimate of 4763 ÷ 82? (a) 6000 (b) 60 (c) 600
  23. 23.Best estimate of 355 ÷ 27? (a) 12 (b) 120 (c) 1200
  24. 24.Best estimate of 6915 ÷ 73? (a) 99 (b) 9900 (c) 990
  25. 25.Best estimate of 2678 ÷ 81? (a) 33 (b) 330 (c) 3300
  26. 26.Best estimate of 1519 ÷ 72? (a) 22 (b) 2200 (c) 220
  27. 27.Best estimate of 474 ÷ 32? (a) 16 (b) 1600 (c) 160
  28. 28.√22 to 1 decimal place? (a) 4.6 (b) 4.8 (c) 4.7 (d) 4.9
  29. 29.√56 to 1 decimal place? (a) 7.6 (b) 7.5 (c) 7.4 (d) 7.3
  30. 30.Best estimate of 2620 ÷ 73? (a) 3700 (b) 37 (c) 370
  31. 31.Best estimate of 3619 ÷ 38? (a) 90 (b) 9000 (c) 900
  32. 32.√70 to 1 decimal place? (a) 8.2 (b) 8.3 (c) 8.4 (d) 8.1
  33. 33.Best estimate of 7760 ÷ 88? (a) 860 (b) 8600 (c) 86
  34. 34.√47 to 1 decimal place? (a) 6.9 (b) 7.0 (c) 6.8 (d) 7.1
  35. 35.√87 to 1 decimal place? (a) 9.2 (b) 9.1 (c) 9.0 (d) 9.3
  36. 36.√21 to 1 decimal place? (a) 4.5 (b) 4.7 (c) 4.6 (d) 4.8
  37. 37.Best estimate of 2550 ÷ 67? (a) 360 (b) 36 (c) 3600
  38. 38.√75 to 1 decimal place? (a) 8.4 (b) 8.6 (c) 8.7 (d) 8.5
  39. 39.Best estimate of 2497 ÷ 39? (a) 62 (b) 620 (c) 6200
  40. 40.Best estimate of 2972 ÷ 47? (a) 590 (b) 59 (c) 5900

Answer key

  1. 6.6
  2. 6.3
  3. 9.8
  4. 8.3
  5. 5.9
  6. 62
  7. 7.8
  8. 34
  9. 44
  10. 5.6
  11. 6.4
  12. 95
  13. 7.3
  14. 69
  15. 4.9
  16. 72
  17. 18
  18. 5.3
  19. 34
  20. 8.5
  21. 89
  22. 60
  23. 12
  24. 99
  25. 33
  26. 22
  27. 16
  28. 4.7
  29. 7.5
  30. 37
  31. 90
  32. 8.4
  33. 86
  34. 6.9
  35. 9.3
  36. 4.6
  37. 36
  38. 8.7
  39. 62
  40. 59

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