Archimedes' Box a.k.a. the Ostomachion The oldest documented puzzle is the Ostomachion. It is attributed to Archimedes who wrote about it some twenty two hundred years ago. His interest may have been an early study of combinatorics. A square is divided into fourteen polygons. There are more than five hundred distinct ways of forming the square. A variety of shapes can be formed by the pieces which may have been originally ivory or bone. The Tangram Some twelve hundred years later, a simpler square dissection puzzle called the Tangram was invented by someone in China during the Song Dynasty. Making shapes with all of the seven pieces, called tans, was the principle focus of the puzzle. Both the early and late 1800s saw the Tangram's rise to great popularity in Europe. More recently and closer to home, the Montessori School employs the Tangram puzzle along with other manipulation toys to promote unstructured learning. The Soma Cube In the 1930s, while enduring a lecture on quantum physics, Piet Hein invented the Soma cube. Soma Cubes include all seven non-convex polycubes of order 3(1) and 4(6). There are 240 distinct solutions to the Soma cube and many other pleasing arrangements are possible. The Diabolical Cube and the Bedlam Cube are other cube dissection puzzles. A pyramid of spheres can be similarly divided and reassembled. Rubik's Cube In 1974, Hungarian sculptor and professor of architecture ErnÅ‘ Rubik invented what he called the Magic Cube. Ideal Toy Corp. marketed it as Rubik's Cube and it quickly became the best selling puzzle ever with more than 400 million sold worldwide. What appears to be a 3x3x3 subdivision of a cube yields 26 smaller cubes facing out. Each visible face of the smaller cube has a sticker whose color corresponds with the side of the larger cube it resides on. The goal of the puzzle is by twisting the faces of the larger cube, return the smaller cubes to their original position where each side of the larger cube is either all red, orange, blue, green, white or yellow. Best selling books have been written on how to solve the cube. Speedcubing competitions have been a display of both dexterity and advanced algorithms for solutions. With a average solve time of 6.45 seconds, Australian Feliks Zemdegs was considered a world record holder. It takes him a few more seconds on average to solve it one handed. Robots have bested his times, but rely on six points of contact.