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Estimating Square Roots and Division Worksheet

Mental maths lesson 27: Estimate divisions and square roots · Set 437 · 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.√88 to 1 decimal place? (a) 9.4 (b) 9.5 (c) 9.7 (d) 9.6
  2. 2.Best estimate of 1943 ÷ 64? (a) 32 (b) 3200 (c) 320
  3. 3.√26 to 1 decimal place? (a) 4.9 (b) 5.1 (c) 5.0 (d) 4.8
  4. 4.Best estimate of 2457 ÷ 63? (a) 41 (b) 4100 (c) 410
  5. 5.Best estimate of 440 ÷ 28? (a) 1500 (b) 150 (c) 15
  6. 6.Best estimate of 3628 ÷ 76? (a) 450 (b) 45 (c) 4500
  7. 7.√66 to 1 decimal place? (a) 8.4 (b) 8.3 (c) 8.2 (d) 8.1
  8. 8.Best estimate of 1577 ÷ 56? (a) 26 (b) 260 (c) 2600
  9. 9.√65 to 1 decimal place? (a) 7.9 (b) 8.1 (c) 7.8 (d) 8.0
  10. 10.Best estimate of 1633 ÷ 76? (a) 200 (b) 20 (c) 2000
  11. 11.Best estimate of 4273 ÷ 78? (a) 5300 (b) 530 (c) 53
  12. 12.Best estimate of 3397 ÷ 73? (a) 49 (b) 490 (c) 4900
  13. 13.Best estimate of 953 ÷ 43? (a) 24 (b) 240 (c) 2400
  14. 14.Best estimate of 1327 ÷ 28? (a) 440 (b) 4400 (c) 44
  15. 15.Best estimate of 1488 ÷ 31? (a) 5000 (b) 50 (c) 500
  16. 16.Best estimate of 6112 ÷ 78? (a) 760 (b) 76 (c) 7600
  17. 17.√61 to 1 decimal place? (a) 8.0 (b) 7.8 (c) 7.9 (d) 7.7
  18. 18.√40 to 1 decimal place? (a) 6.3 (b) 6.2 (c) 6.1 (d) 6.0
  19. 19.Best estimate of 2364 ÷ 77? (a) 30 (b) 300 (c) 3000
  20. 20.√83 to 1 decimal place? (a) 9.2 (b) 9.0 (c) 9.1 (d) 8.9
  21. 21.√44 to 1 decimal place? (a) 6.7 (b) 6.5 (c) 6.6 (d) 6.4
  22. 22.Best estimate of 3330 ÷ 76? (a) 42 (b) 4200 (c) 420
  23. 23.Best estimate of 678 ÷ 26? (a) 23 (b) 2300 (c) 230
  24. 24.√53 to 1 decimal place? (a) 7.2 (b) 7.0 (c) 7.1 (d) 7.3
  25. 25.Best estimate of 3129 ÷ 78? (a) 3900 (b) 390 (c) 39
  26. 26.Best estimate of 4339 ÷ 72? (a) 620 (b) 6200 (c) 62
  27. 27.Best estimate of 2118 ÷ 27? (a) 7100 (b) 710 (c) 71
  28. 28.Best estimate of 3896 ÷ 73? (a) 5600 (b) 560 (c) 56
  29. 29.√50 to 1 decimal place? (a) 7.0 (b) 7.1 (c) 6.9 (d) 6.8
  30. 30.√62 to 1 decimal place? (a) 8.0 (b) 8.2 (c) 8.1 (d) 7.9
  31. 31.Best estimate of 878 ÷ 37? (a) 22 (b) 2200 (c) 220
  32. 32.Best estimate of 2183 ÷ 24? (a) 10900 (b) 1090 (c) 109
  33. 33.√94 to 1 decimal place? (a) 9.5 (b) 9.7 (c) 9.6 (d) 9.4
  34. 34.√89 to 1 decimal place? (a) 9.5 (b) 9.7 (c) 9.6 (d) 9.4
  35. 35.√48 to 1 decimal place? (a) 7.0 (b) 7.1 (c) 6.9 (d) 6.8
  36. 36.Best estimate of 2772 ÷ 63? (a) 460 (b) 4600 (c) 46
  37. 37.Best estimate of 754 ÷ 39? (a) 190 (b) 1900 (c) 19
  38. 38.√72 to 1 decimal place? (a) 8.6 (b) 8.7 (c) 8.5 (d) 8.8
  39. 39.√52 to 1 decimal place? (a) 7.1 (b) 7.3 (c) 7.4 (d) 7.2
  40. 40.√42 to 1 decimal place? (a) 6.5 (b) 6.4 (c) 6.3 (d) 6.2

Answer key

  1. 9.4
  2. 32
  3. 5.1
  4. 41
  5. 15
  6. 45
  7. 8.1
  8. 26
  9. 8.1
  10. 20
  11. 53
  12. 49
  13. 24
  14. 44
  15. 50
  16. 76
  17. 7.8
  18. 6.3
  19. 30
  20. 9.1
  21. 6.6
  22. 42
  23. 23
  24. 7.3
  25. 39
  26. 62
  27. 71
  28. 56
  29. 7.1
  30. 7.9
  31. 22
  32. 109
  33. 9.7
  34. 9.4
  35. 6.9
  36. 46
  37. 19
  38. 8.5
  39. 7.2
  40. 6.5

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