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Squares Trick Worksheet

Speed calculation lesson 10: Squares next to a ten · Set 821 · 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. 1.71² =
  2. 2.59² =
  3. 3.71² =
  4. 4.61² =
  5. 5.19² =
  6. 6.91² =
  7. 7.31² =
  8. 8.71² =
  9. 9.39² =
  10. 10.69² =
  11. 11.61² =
  12. 12.89² =
  13. 13.69² =
  14. 14.29² =
  15. 15.81² =
  16. 16.31² =
  17. 17.49² =
  18. 18.81² =
  19. 19.39² =
  20. 20.81² =
  21. 21.59² =
  22. 22.91² =
  23. 23.21² =
  24. 24.39² =
  25. 25.61² =
  26. 26.71² =
  27. 27.79² =
  28. 28.49² =
  29. 29.49² =
  30. 30.31² =
  31. 31.61² =
  32. 32.59² =
  33. 33.91² =
  34. 34.79² =
  35. 35.59² =
  36. 36.79² =
  37. 37.69² =
  38. 38.29² =
  39. 39.91² =
  40. 40.31² =

Answer key

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

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