← Estimate divisions and square roots lesson New set →

Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 882 · 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.√74 to 1 decimal place? (a) 8.7 (b) 8.9 (c) 8.8 (d) 8.6
  2. 2.√89 to 1 decimal place? (a) 9.4 (b) 9.3 (c) 9.6 (d) 9.5
  3. 3.√27 to 1 decimal place? (a) 5.2 (b) 5.3 (c) 5.1 (d) 5.4
  4. 4.Best estimate of 2464 ÷ 39? (a) 62 (b) 620 (c) 6200
  5. 5.√29 to 1 decimal place? (a) 5.2 (b) 5.4 (c) 5.5 (d) 5.3
  6. 6.Best estimate of 1004 ÷ 62? (a) 1700 (b) 170 (c) 17
  7. 7.Best estimate of 2868 ÷ 36? (a) 72 (b) 720 (c) 7200
  8. 8.Best estimate of 2616 ÷ 28? (a) 8700 (b) 870 (c) 87
  9. 9.√84 to 1 decimal place? (a) 9.4 (b) 9.5 (c) 9.2 (d) 9.3
  10. 10.Best estimate of 3345 ÷ 58? (a) 5600 (b) 560 (c) 56
  11. 11.Best estimate of 917 ÷ 66? (a) 130 (b) 1300 (c) 13
  12. 12.√31 to 1 decimal place? (a) 5.6 (b) 5.5 (c) 5.3 (d) 5.4
  13. 13.Best estimate of 1845 ÷ 57? (a) 310 (b) 31 (c) 3100
  14. 14.Best estimate of 1286 ÷ 44? (a) 32 (b) 320 (c) 3200
  15. 15.Best estimate of 6410 ÷ 73? (a) 92 (b) 9200 (c) 920
  16. 16.√22 to 1 decimal place? (a) 4.4 (b) 4.7 (c) 4.5 (d) 4.6
  17. 17.√72 to 1 decimal place? (a) 8.5 (b) 8.4 (c) 8.2 (d) 8.3
  18. 18.Best estimate of 671 ÷ 23? (a) 3400 (b) 340 (c) 34
  19. 19.Best estimate of 5195 ÷ 56? (a) 870 (b) 8700 (c) 87
  20. 20.Best estimate of 1266 ÷ 32? (a) 42 (b) 420 (c) 4200
  21. 21.Best estimate of 4257 ÷ 66? (a) 6100 (b) 610 (c) 61
  22. 22.Best estimate of 1485 ÷ 52? (a) 3000 (b) 30 (c) 300
  23. 23.Best estimate of 634 ÷ 31? (a) 2100 (b) 210 (c) 21
  24. 24.Best estimate of 5065 ÷ 53? (a) 101 (b) 10100 (c) 1010
  25. 25.√69 to 1 decimal place? (a) 8.4 (b) 8.2 (c) 8.5 (d) 8.3
  26. 26.Best estimate of 1215 ÷ 64? (a) 200 (b) 20 (c) 2000
  27. 27.Best estimate of 1522 ÷ 86? (a) 170 (b) 1700 (c) 17
  28. 28.Best estimate of 2244 ÷ 26? (a) 75 (b) 7500 (c) 750
  29. 29.√71 to 1 decimal place? (a) 8.5 (b) 8.6 (c) 8.7 (d) 8.4
  30. 30.Best estimate of 2167 ÷ 42? (a) 54 (b) 540 (c) 5400
  31. 31.Best estimate of 532 ÷ 29? (a) 1800 (b) 180 (c) 18
  32. 32.√61 to 1 decimal place? (a) 7.7 (b) 7.9 (c) 7.6 (d) 7.8
  33. 33.Best estimate of 1515 ÷ 43? (a) 380 (b) 38 (c) 3800
  34. 34.√46 to 1 decimal place? (a) 6.5 (b) 6.7 (c) 6.8 (d) 6.6
  35. 35.√45 to 1 decimal place? (a) 6.7 (b) 6.5 (c) 6.6 (d) 6.4
  36. 36.√75 to 1 decimal place? (a) 9.0 (b) 8.8 (c) 8.7 (d) 8.9
  37. 37.Best estimate of 1984 ÷ 31? (a) 660 (b) 6600 (c) 66
  38. 38.Best estimate of 908 ÷ 74? (a) 13 (b) 1300 (c) 130
  39. 39.√37 to 1 decimal place? (a) 6.2 (b) 6.3 (c) 6.1 (d) 6.0
  40. 40.Best estimate of 600 ÷ 36? (a) 15 (b) 150 (c) 1500

Answer key

  1. 8.6
  2. 9.4
  3. 5.2
  4. 62
  5. 5.4
  6. 17
  7. 72
  8. 87
  9. 9.2
  10. 56
  11. 13
  12. 5.6
  13. 31
  14. 32
  15. 92
  16. 4.7
  17. 8.5
  18. 34
  19. 87
  20. 42
  21. 61
  22. 30
  23. 21
  24. 101
  25. 8.3
  26. 20
  27. 17
  28. 75
  29. 8.4
  30. 54
  31. 18
  32. 7.8
  33. 38
  34. 6.8
  35. 6.7
  36. 8.7
  37. 66
  38. 13
  39. 6.1
  40. 15

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