Venn Puzzler

Venn Puzzler

Is this Venn-like diagram a good fit for Reptile, Crocodile, Female? Does this make sense? No – it suggests that some Crocodiles are not Reptiles. WRONG. It also suggests that all Crocodiles are Females. WRONG. Fix it… This works. Some Crocodiles and...
Hex (strategy game)

Hex (strategy game)

Hex (Piet Hein, 1942) I’ve been using a small variant of hex in the age 5 to 7 classroom for several years. Apart from the smaller size, the only other innovation is to insist that the first player plays on the perimeter on their first move. Without a rule like...
Puppet Puzzle (counting, logic, proof)

Puppet Puzzle (counting, logic, proof)

Jayadratha (जयद्रथ), the envious tyrant of Sindhu, was reclining on his fifteen pillows, trying to get comfortable – and failing. He suddenly realized the reason… The stacks of pillows needed to decrease in height from left to right. This was easy…...
Armenian Rug Puzzles (logic)

Armenian Rug Puzzles (logic)

Armenian rugs cover the floor – sometimes laying atop each other. A whole lot of puzzles arise from trying to find the shape and placement of these rugs. PS. The photo is of the oldest pile rug to be discovered – 2500 years old. It is Armenian, but was...