4 December

There are 5 ways to tile a 3×2 rectangle with 2×2 squares and 2×1 dominos.
Today's number is the number of ways to tile a 9×2 rectangle with 2×2 squares and 2×1 dominos.

Show answer


Show me a random puzzle
 Most recent collections 

Advent calendar 2019

Sunday Afternoon Maths LXVII

Coloured weights
Not Roman numerals

Advent calendar 2018

Sunday Afternoon Maths LXVI

Cryptic crossnumber #2

List of all puzzles


median chocolate books ellipses probability products sport hexagons rugby prime numbers dominos triangles arrows partitions christmas menace spheres routes balancing complex numbers taxicab geometry coordinates number means coins multiplication 2d shapes sum to infinity proportion differentiation graphs speed angles tiling advent shapes integration 3d shapes averages cards area floors folding tube maps perimeter regular shapes lines shape square roots factorials volume factors the only crossnumber money indices calculus ave logic parabolas wordplay cryptic clues elections triangle numbers colouring squares chess symmetry surds star numbers perfect numbers digital clocks crossnumbers scales quadratics fractions digits palindromes division time pascal's triangle crosswords people maths cube numbers circles rectangles algebra integers range bases cryptic crossnumbers trigonometry dice dates clocks chalkdust crossnumber percentages doubling irreducible numbers gerrymandering odd numbers crossnumber square numbers polygons geometry functions games remainders multiples numbers grids probabilty dodecagons sums sequences addition planes mean unit fractions


Show me a random puzzle
▼ show ▼
© Matthew Scroggs 2012–2020