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Squares Trick Worksheet

Speed calculation lesson 10: Squares next to a ten · Set 819 · 40 questions
TalentJR

The fast method (Step from a neighbour): Find the round neighbour and square it: 70² = 7 × 7 = 49, then two 0s → 4900. Ends in 1 (one more)? Add the round number and the number: 4900 + 70 + 71. Ends in 9 (one less)? Take them away: 69² = 4900 − 70 − 69 = 4761.

NameDateTime takenScore ___ / 40
  1. 1.69² =
  2. 2.31² =
  3. 3.41² =
  4. 4.51² =
  5. 5.69² =
  6. 6.29² =
  7. 7.29² =
  8. 8.91² =
  9. 9.69² =
  10. 10.71² =
  11. 11.21² =
  12. 12.91² =
  13. 13.49² =
  14. 14.49² =
  15. 15.59² =
  16. 16.79² =
  17. 17.21² =
  18. 18.79² =
  19. 19.39² =
  20. 20.71² =
  21. 21.61² =
  22. 22.91² =
  23. 23.51² =
  24. 24.39² =
  25. 25.91² =
  26. 26.19² =
  27. 27.79² =
  28. 28.91² =
  29. 29.39² =
  30. 30.61² =
  31. 31.71² =
  32. 32.49² =
  33. 33.81² =
  34. 34.41² =
  35. 35.71² =
  36. 36.41² =
  37. 37.49² =
  38. 38.71² =
  39. 39.39² =
  40. 40.89² =

Answer key

  1. 4761
  2. 961
  3. 1681
  4. 2601
  5. 4761
  6. 841
  7. 841
  8. 8281
  9. 4761
  10. 5041
  11. 441
  12. 8281
  13. 2401
  14. 2401
  15. 3481
  16. 6241
  17. 441
  18. 6241
  19. 1521
  20. 5041
  21. 3721
  22. 8281
  23. 2601
  24. 1521
  25. 8281
  26. 361
  27. 6241
  28. 8281
  29. 1521
  30. 3721
  31. 5041
  32. 2401
  33. 6561
  34. 1681
  35. 5041
  36. 1681
  37. 2401
  38. 5041
  39. 1521
  40. 7921

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