← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 480 · 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.√96 to 1 decimal place? (a) 9.8 (b) 9.7 (c) 10.0 (d) 9.9
  2. 2.Best estimate of 1094 ÷ 24? (a) 55 (b) 550 (c) 5500
  3. 3.Best estimate of 1486 ÷ 32? (a) 500 (b) 5000 (c) 50
  4. 4.Best estimate of 1686 ÷ 52? (a) 3400 (b) 34 (c) 340
  5. 5.√89 to 1 decimal place? (a) 9.3 (b) 9.2 (c) 9.4 (d) 9.1
  6. 6.Best estimate of 2961 ÷ 32? (a) 990 (b) 9900 (c) 99
  7. 7.Best estimate of 1343 ÷ 74? (a) 190 (b) 1900 (c) 19
  8. 8.Best estimate of 1959 ÷ 64? (a) 3300 (b) 330 (c) 33
  9. 9.√21 to 1 decimal place? (a) 4.8 (b) 4.6 (c) 4.5 (d) 4.7
  10. 10.√48 to 1 decimal place? (a) 6.8 (b) 7.0 (c) 6.9 (d) 7.1
  11. 11.√75 to 1 decimal place? (a) 8.8 (b) 8.6 (c) 8.5 (d) 8.7
  12. 12.√77 to 1 decimal place? (a) 8.8 (b) 8.9 (c) 8.7 (d) 9.0
  13. 13.√31 to 1 decimal place? (a) 5.9 (b) 5.8 (c) 5.7 (d) 5.6
  14. 14.Best estimate of 1214 ÷ 39? (a) 3000 (b) 30 (c) 300
  15. 15.√58 to 1 decimal place? (a) 7.6 (b) 7.7 (c) 7.8 (d) 7.9
  16. 16.Best estimate of 2895 ÷ 46? (a) 5800 (b) 58 (c) 580
  17. 17.Best estimate of 2285 ÷ 28? (a) 760 (b) 7600 (c) 76
  18. 18.Best estimate of 704 ÷ 26? (a) 230 (b) 2300 (c) 23
  19. 19.Best estimate of 880 ÷ 46? (a) 1800 (b) 18 (c) 180
  20. 20.Best estimate of 4987 ÷ 56? (a) 8300 (b) 83 (c) 830
  21. 21.√78 to 1 decimal place? (a) 8.9 (b) 8.8 (c) 9.1 (d) 9.0
  22. 22.√84 to 1 decimal place? (a) 9.0 (b) 9.1 (c) 9.3 (d) 9.2
  23. 23.Best estimate of 2602 ÷ 42? (a) 65 (b) 650 (c) 6500
  24. 24.Best estimate of 2067 ÷ 58? (a) 34 (b) 340 (c) 3400
  25. 25.Best estimate of 1406 ÷ 26? (a) 4700 (b) 47 (c) 470
  26. 26.√88 to 1 decimal place? (a) 9.5 (b) 9.6 (c) 9.7 (d) 9.4
  27. 27.Best estimate of 4733 ÷ 62? (a) 7900 (b) 790 (c) 79
  28. 28.√24 to 1 decimal place? (a) 5.0 (b) 4.9 (c) 5.2 (d) 5.1
  29. 29.Best estimate of 2945 ÷ 47? (a) 590 (b) 5900 (c) 59
  30. 30.√87 to 1 decimal place? (a) 9.2 (b) 9.3 (c) 9.5 (d) 9.4
  31. 31.Best estimate of 3031 ÷ 72? (a) 430 (b) 43 (c) 4300
  32. 32.Best estimate of 1284 ÷ 21? (a) 6400 (b) 640 (c) 64
  33. 33.√34 to 1 decimal place? (a) 5.5 (b) 5.7 (c) 5.6 (d) 5.8
  34. 34.Best estimate of 2831 ÷ 63? (a) 470 (b) 4700 (c) 47
  35. 35.√26 to 1 decimal place? (a) 5.2 (b) 5.4 (c) 5.1 (d) 5.3
  36. 36.Best estimate of 1228 ÷ 27? (a) 4100 (b) 410 (c) 41
  37. 37.Best estimate of 1277 ÷ 39? (a) 3200 (b) 320 (c) 32
  38. 38.Best estimate of 3371 ÷ 67? (a) 480 (b) 48 (c) 4800
  39. 39.Best estimate of 3740 ÷ 72? (a) 53 (b) 530 (c) 5300
  40. 40.√74 to 1 decimal place? (a) 8.9 (b) 8.6 (c) 8.7 (d) 8.8

Answer key

  1. 9.8
  2. 55
  3. 50
  4. 34
  5. 9.4
  6. 99
  7. 19
  8. 33
  9. 4.6
  10. 6.9
  11. 8.7
  12. 8.8
  13. 5.6
  14. 30
  15. 7.6
  16. 58
  17. 76
  18. 23
  19. 18
  20. 83
  21. 8.8
  22. 9.2
  23. 65
  24. 34
  25. 47
  26. 9.4
  27. 79
  28. 4.9
  29. 59
  30. 9.3
  31. 43
  32. 64
  33. 5.8
  34. 47
  35. 5.1
  36. 41
  37. 32
  38. 48
  39. 53
  40. 8.6

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