Put-Together - Pentominoes

Craftsman:Wayne Daniel
Pieces:12 pentominoes, plus 4 single squares, plus the tray

In 1954, Dr. Solomon Golomb coined the term "polyomino" in an article titled Checker Boards and Polyominoes for the American Mathematical Monthly while he was a graduate student at Harvard University. Subsequently, he wrote a book, Polyominoes, which included a plastic set in an insert in the back. A revised edition was published in 1994 (without the pieces). Besides his article, they were first extensively discussed in Scientific American in 1957 and they have since become an area of extensive research by puzzle and recreational mathematics enthusiasts.
The twelve pieces represent all of the ways five squares can be arranged. The most common objective is to make an 8x8 square with the four corners missing. there are only two solutions. Other 8x8 problems involve leaving empty squares at symmetrical locations. The number of problems and their analysis would be a book all by itself - which, I suppose, is why Dr. Golomb wrote one.
Solid Pentominoes are the same piece arrangement, but using cubes which results in a three-dimensional puzzle.
More information in The Puzzling World of Polyhedral Dissections