← Back to lesson·Advance A · W1 D3 · 2 drill sections · ~4 min

Advance A · Week 1 · Fundamentals

Day 3 Practice Worksheet — Mental Math Shortcuts: ×9, ×11

The lightning-fast logic for specific multipliers.

Name
Date
Score

  1. §1× 11 rule

    ⏱ 2 min · 20 problems

    Timed drill — start a 2-minute timer, then solve in order. Goal: finish under time with full accuracy.

    1. 01.76 × 11=
    2. 02.83 × 11=
    3. 03.85 × 11=
    4. 04.62 × 11=
    5. 05.82 × 11=
    6. 06.93 × 11=
    7. 07.89 × 11=
    8. 08.32 × 11=
    9. 09.83 × 11=
    10. 10.66 × 11=
    11. 11.76 × 11=
    12. 12.61 × 11=
    13. 13.79 × 11=
    14. 14.41 × 11=
    15. 15.96 × 11=
    16. 16.34 × 11=
    17. 17.45 × 11=
    18. 18.22 × 11=
    19. 19.54 × 11=
    20. 20.58 × 11=

  2. §2× 9 rule

    ⏱ 2 min · 20 problems

    Timed drill — start a 2-minute timer, then solve in order. Goal: finish under time with full accuracy.

    1. 01.15 × 9=
    2. 02.22 × 9=
    3. 03.81 × 9=
    4. 04.38 × 9=
    5. 05.48 × 9=
    6. 06.22 × 9=
    7. 07.25 × 9=
    8. 08.87 × 9=
    9. 09.98 × 9=
    10. 10.34 × 9=
    11. 11.24 × 9=
    12. 12.37 × 9=
    13. 13.36 × 9=
    14. 14.54 × 9=
    15. 15.88 × 9=
    16. 16.38 × 9=
    17. 17.46 × 9=
    18. 18.61 × 9=
    19. 19.67 × 9=
    20. 20.93 × 9=

Answer Key

§1 · × 11 rule

  1. 1.836
  2. 2.913
  3. 3.935
  4. 4.682
  5. 5.902
  6. 6.1023
  7. 7.979
  8. 8.352
  9. 9.913
  10. 10.726
  11. 11.836
  12. 12.671
  13. 13.869
  14. 14.451
  15. 15.1056
  16. 16.374
  17. 17.495
  18. 18.242
  19. 19.594
  20. 20.638

§2 · × 9 rule

  1. 1.135
  2. 2.198
  3. 3.729
  4. 4.342
  5. 5.432
  6. 6.198
  7. 7.225
  8. 8.783
  9. 9.882
  10. 10.306
  11. 11.216
  12. 12.333
  13. 13.324
  14. 14.486
  15. 15.792
  16. 16.342
  17. 17.414
  18. 18.549
  19. 19.603
  20. 20.837