← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 614 · 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 4107 ÷ 48? (a) 820 (b) 82 (c) 8200
  2. 2.√77 to 1 decimal place? (a) 8.8 (b) 8.7 (c) 8.9 (d) 9.0
  3. 3.Best estimate of 3760 ÷ 56? (a) 6300 (b) 630 (c) 63
  4. 4.Best estimate of 1974 ÷ 36? (a) 4900 (b) 490 (c) 49
  5. 5.√75 to 1 decimal place? (a) 8.6 (b) 8.7 (c) 8.5 (d) 8.4
  6. 6.Best estimate of 2033 ÷ 69? (a) 29 (b) 2900 (c) 290
  7. 7.Best estimate of 2399 ÷ 26? (a) 80 (b) 8000 (c) 800
  8. 8.√31 to 1 decimal place? (a) 5.6 (b) 5.4 (c) 5.5 (d) 5.7
  9. 9.Best estimate of 1470 ÷ 39? (a) 3700 (b) 37 (c) 370
  10. 10.√23 to 1 decimal place? (a) 4.8 (b) 4.9 (c) 5.0 (d) 4.7
  11. 11.√26 to 1 decimal place? (a) 5.0 (b) 4.9 (c) 5.1 (d) 4.8
  12. 12.Best estimate of 1492 ÷ 33? (a) 50 (b) 500 (c) 5000
  13. 13.Best estimate of 1796 ÷ 26? (a) 600 (b) 6000 (c) 60
  14. 14.√50 to 1 decimal place? (a) 7.4 (b) 7.2 (c) 7.1 (d) 7.3
  15. 15.Best estimate of 1549 ÷ 22? (a) 77 (b) 7700 (c) 770
  16. 16.Best estimate of 4325 ÷ 68? (a) 62 (b) 6200 (c) 620
  17. 17.Best estimate of 1525 ÷ 58? (a) 25 (b) 2500 (c) 250
  18. 18.Best estimate of 3028 ÷ 53? (a) 61 (b) 6100 (c) 610
  19. 19.Best estimate of 1234 ÷ 81? (a) 15 (b) 1500 (c) 150
  20. 20.√69 to 1 decimal place? (a) 8.5 (b) 8.4 (c) 8.2 (d) 8.3
  21. 21.Best estimate of 970 ÷ 22? (a) 490 (b) 4900 (c) 49
  22. 22.Best estimate of 2015 ÷ 22? (a) 101 (b) 1010 (c) 10100
  23. 23.Best estimate of 4902 ÷ 61? (a) 820 (b) 82 (c) 8200
  24. 24.Best estimate of 1919 ÷ 21? (a) 960 (b) 96 (c) 9600
  25. 25.Best estimate of 1475 ÷ 66? (a) 210 (b) 2100 (c) 21
  26. 26.Best estimate of 1468 ÷ 22? (a) 730 (b) 73 (c) 7300
  27. 27.√42 to 1 decimal place? (a) 6.5 (b) 6.6 (c) 6.7 (d) 6.8
  28. 28.Best estimate of 1803 ÷ 28? (a) 6000 (b) 600 (c) 60
  29. 29.Best estimate of 1443 ÷ 58? (a) 240 (b) 24 (c) 2400
  30. 30.Best estimate of 3064 ÷ 48? (a) 6100 (b) 61 (c) 610
  31. 31.Best estimate of 682 ÷ 22? (a) 3400 (b) 34 (c) 340
  32. 32.√51 to 1 decimal place? (a) 6.9 (b) 7.2 (c) 7.0 (d) 7.1
  33. 33.√94 to 1 decimal place? (a) 9.5 (b) 9.6 (c) 9.7 (d) 9.8
  34. 34.√80 to 1 decimal place? (a) 8.7 (b) 9.0 (c) 8.8 (d) 8.9
  35. 35.√70 to 1 decimal place? (a) 8.6 (b) 8.7 (c) 8.4 (d) 8.5
  36. 36.√55 to 1 decimal place? (a) 7.6 (b) 7.7 (c) 7.4 (d) 7.5
  37. 37.√96 to 1 decimal place? (a) 10.1 (b) 9.8 (c) 10.0 (d) 9.9
  38. 38.Best estimate of 2886 ÷ 42? (a) 7200 (b) 720 (c) 72
  39. 39.Best estimate of 1589 ÷ 28? (a) 53 (b) 5300 (c) 530
  40. 40.Best estimate of 2681 ÷ 28? (a) 89 (b) 8900 (c) 890

Answer key

  1. 82
  2. 8.8
  3. 63
  4. 49
  5. 8.7
  6. 29
  7. 80
  8. 5.6
  9. 37
  10. 4.8
  11. 5.1
  12. 50
  13. 60
  14. 7.1
  15. 77
  16. 62
  17. 25
  18. 61
  19. 15
  20. 8.3
  21. 49
  22. 101
  23. 82
  24. 96
  25. 21
  26. 73
  27. 6.5
  28. 60
  29. 24
  30. 61
  31. 34
  32. 7.1
  33. 9.7
  34. 8.9
  35. 8.4
  36. 7.4
  37. 9.8
  38. 72
  39. 53
  40. 89

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