Adders Puzzle Once Owned by Olive C. Hazlett

This example of Adders, a set of four puzzles, belonged to Olive C. Hazlett (1890–1974). Hazlett was one of America's leading mathematicians during the 1920s. She taught at Bryn Mawr College, Mount Holyoke College, and the University of Illinois, after which she moved to Peterborough, New Hampshire. This and other of her puzzles and books of puzzles were collected from a community of Discalced Carmelite brothers who had lived in New Hampshire and who had befriended Hazlett there.

Adders was made by the Douglass Novelty Company of Detroit, Michigan, and sold for ten cents. The box contains a shiny green cardboard playing board and twelve small silver cardboard discs, three blank and the others numbered 1 through 9. The directions for the four different puzzles are printed on the inside of the cover of the box. The playing board is square and has various lines and circles marked on it. Three of the four puzzles involve placing the numbered discs in specified ways so that specified sets of discs add to a given number.

Adders was probably made in about 1930, since another set of puzzles in the collections, Kangaroo (2015.0027.07), was made about then by the same company and has very similar packaging, playing board, and discs.

The first puzzle has many solutions, all of which are related to the three-by-three magic square, which is known as the Lo Shu square. That square—in which the rows, columns, and diagonals all add up to 15—appears in Chinese literature dating back to 650 BCE. Some of the solutions are equivalent to the Lo Shu square, and all the other solutions can be derived from a solution equivalent to the Lo Shu square by switching two discs, neither of which lies in the center of the circle, but are on the same line through the center of the circle.

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