← Pattern Anatomy

Competition · AMC preparation · step 4 of 4

Pattern Anatomy

Each pattern, deconstructed.

tiling-packing-divisibility

★ Rank 19/25 0.5% of all AMC problems Grade 4–4

A geometric region must be covered or partitioned by pieces subject to area / divisibility constraints. The decisive observation is usually arithmetic: total area mod tile-area gives the minimum waste, or the constrained items must fit inside a small bounding rectangle.

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27-year frequency
1999–2026 ↑ 300%
2026 forecast slots
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How to solve

Primary tools see-drawmath-toolssimplify
What to look for
  • Change grid_dimensions to 4x9 and reuse the same tile set — the mod-4 leftover shifts to a different value
  • Replace 1x4 with 1x3 tiles to change divisor_d from 4 to 3
  • For an extremal-configuration variant, ask for the MAXIMUM number of clean rows/cols instead of minimum

Sub-archetype mix (3)

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More data (year-over-year, tool fingerprint, grade distribution, all members)
14
members
1999–2026
Active years
Year-over-year

Tool fingerprint (1–17)

Grade distribution

  • Gr 3
    3
  • Gr 4
    5
  • Gr 5
    2