← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 958 · 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 2742 ÷ 41? (a) 6900 (b) 69 (c) 690
  2. 2.√72 to 1 decimal place? (a) 8.5 (b) 8.3 (c) 8.4 (d) 8.2
  3. 3.√23 to 1 decimal place? (a) 4.7 (b) 4.5 (c) 4.6 (d) 4.8
  4. 4.√22 to 1 decimal place? (a) 4.8 (b) 4.5 (c) 4.7 (d) 4.6
  5. 5.Best estimate of 3429 ÷ 86? (a) 38 (b) 380 (c) 3800
  6. 6.√28 to 1 decimal place? (a) 5.1 (b) 5.2 (c) 5.4 (d) 5.3
  7. 7.Best estimate of 4226 ÷ 52? (a) 850 (b) 8500 (c) 85
  8. 8.√84 to 1 decimal place? (a) 9.1 (b) 9.3 (c) 9.0 (d) 9.2
  9. 9.Best estimate of 5831 ÷ 76? (a) 73 (b) 730 (c) 7300
  10. 10.Best estimate of 2077 ÷ 23? (a) 1040 (b) 104 (c) 10400
  11. 11.√56 to 1 decimal place? (a) 7.4 (b) 7.6 (c) 7.3 (d) 7.5
  12. 12.√58 to 1 decimal place? (a) 7.4 (b) 7.5 (c) 7.6 (d) 7.7
  13. 13.√80 to 1 decimal place? (a) 9.1 (b) 9.0 (c) 9.2 (d) 8.9
  14. 14.Best estimate of 3091 ÷ 48? (a) 6200 (b) 620 (c) 62
  15. 15.Best estimate of 1813 ÷ 66? (a) 26 (b) 2600 (c) 260
  16. 16.√75 to 1 decimal place? (a) 8.9 (b) 9.0 (c) 8.7 (d) 8.8
  17. 17.√37 to 1 decimal place? (a) 6.1 (b) 6.2 (c) 6.3 (d) 6.0
  18. 18.Best estimate of 798 ÷ 31? (a) 2700 (b) 270 (c) 27
  19. 19.Best estimate of 1383 ÷ 52? (a) 280 (b) 2800 (c) 28
  20. 20.√26 to 1 decimal place? (a) 5.1 (b) 5.0 (c) 5.2 (d) 5.3
  21. 21.√65 to 1 decimal place? (a) 8.3 (b) 8.2 (c) 8.4 (d) 8.1
  22. 22.Best estimate of 939 ÷ 56? (a) 1600 (b) 160 (c) 16
  23. 23.Best estimate of 1822 ÷ 46? (a) 360 (b) 36 (c) 3600
  24. 24.√98 to 1 decimal place? (a) 10.1 (b) 9.9 (c) 9.8 (d) 10.0
  25. 25.√34 to 1 decimal place? (a) 5.6 (b) 5.7 (c) 5.9 (d) 5.8
  26. 26.√46 to 1 decimal place? (a) 6.9 (b) 6.6 (c) 6.7 (d) 6.8
  27. 27.Best estimate of 2669 ÷ 61? (a) 44 (b) 4400 (c) 440
  28. 28.√50 to 1 decimal place? (a) 7.1 (b) 7.2 (c) 7.3 (d) 7.0
  29. 29.√69 to 1 decimal place? (a) 8.5 (b) 8.4 (c) 8.3 (d) 8.6
  30. 30.√76 to 1 decimal place? (a) 8.8 (b) 8.7 (c) 8.9 (d) 8.6
  31. 31.√96 to 1 decimal place? (a) 9.7 (b) 9.9 (c) 9.8 (d) 9.6
  32. 32.Best estimate of 3755 ÷ 62? (a) 6300 (b) 630 (c) 63
  33. 33.√94 to 1 decimal place? (a) 9.6 (b) 9.7 (c) 9.9 (d) 9.8
  34. 34.√31 to 1 decimal place? (a) 5.6 (b) 5.5 (c) 5.7 (d) 5.4
  35. 35.√89 to 1 decimal place? (a) 9.2 (b) 9.1 (c) 9.4 (d) 9.3
  36. 36.√61 to 1 decimal place? (a) 7.8 (b) 7.7 (c) 7.6 (d) 7.5
  37. 37.√55 to 1 decimal place? (a) 7.4 (b) 7.7 (c) 7.5 (d) 7.6
  38. 38.Best estimate of 710 ÷ 36? (a) 1800 (b) 180 (c) 18
  39. 39.Best estimate of 735 ÷ 26? (a) 25 (b) 2500 (c) 250
  40. 40.Best estimate of 2143 ÷ 68? (a) 3100 (b) 310 (c) 31

Answer key

  1. 69
  2. 8.5
  3. 4.8
  4. 4.7
  5. 38
  6. 5.3
  7. 85
  8. 9.2
  9. 73
  10. 104
  11. 7.5
  12. 7.6
  13. 8.9
  14. 62
  15. 26
  16. 8.7
  17. 6.1
  18. 27
  19. 28
  20. 5.1
  21. 8.1
  22. 16
  23. 36
  24. 9.9
  25. 5.8
  26. 6.8
  27. 44
  28. 7.1
  29. 8.3
  30. 8.7
  31. 9.8
  32. 63
  33. 9.7
  34. 5.6
  35. 9.4
  36. 7.8
  37. 7.4
  38. 18
  39. 25
  40. 31

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