To create the five Platonic solids, you can cut paper and then fold it. One of the best ways to do this is to cut…
The LCD numbers on a stair climber or alarm clock or microwave are made up of straight sections arranged either horizontally and/or vertically. That is,…
On Thursday January 20th the Pocono Mountain region experienced the first big snow storm of the new millennium. Many schools closed because of the slippery…
There is a number 6 on the tip of the triangle. Arrange the numbers 1, 2, 3, 4 and 5 such that the sum of…
Equipment: Pieces numbered 1 through 25 and a 5×5 board. Number of Players: 2 (a cobra player, and a snake charmer) Time: 10 minutes How…
A siege is a blockade of a town, city or fortress to try to make it surrender. One of the greatest practitioners of the siege…
Sally is a sleepwalker. Each night she gets up without knowing it, puts on her slippers and coat, and wanders around her village for an…
Coyotes demarcate their territory by peeing on bushes, rocks, shrubs, cacti, trees, and anything else that is lying around. It is tiring, never-ending work. That…
Human cities, especially newer ones are usually organized with orthogonal (right-angled) streets and avenues. Here is an example from Gaza: Robot cities are similar to…
Write 1’s and 2’s in the circles so that no three consecutive numbers sum to a multiple of three. Extensions: There are four solutions to…