Marjorie Rice

Marjorie Ruth Rice (née Jeuck, 1923–2017) was an American amateur mathematician most famous for her discoveries of pentagonal tilings.

Background Rice was born February 16, 1923, in St. Petersburg, Florida. mother of five, who had become an ardent follower of Martin Gardner's long-running column, "Mathematical Games", which appeared monthly, 1957–1986, in the pages of Scientific American magazine. By the 1970s, Gardner was a popular science writer and amateur mathematician. Rice said later that she would rush to grab each issue from the mail before anyone else could get it, especially her son who subscribed to the magazine.

In 1975, Rice read Gardner's July column, "On Tessellating the Plane with Convex Polygon Tiles", Gardner was repeating Kershner's claim that the list of convex pentagon tilers was complete. But within a month, Gardner received an example, by one of his readers, Richard James III, of a new convex pentagon tiler, and published this news in his December 1975 column.

Discoveries of pentagonal tilings

Inspired by this new discovery, Rice decided to try to find other new pentagon tilers. Despite having only a high-school education, but a keen interest in art, she began devoting her free time to discovering new pentagonal tilings, ways to tile a plane using pentagons. She worked on the problem in her free time and through the 1975 holiday season "by drawing diagrams on the kitchen table when no one was around and hiding them when her husband and children came home, or when friends stopped by". By December 1976, she had discovered two additional new types of tessellating pentagons and over 75 distinct tessellations by pentagons that were in blocks that could be seen as "double hexagons". In December 1977, she made her fourth discovery of a new type of pentagon tile and by then had enumerated 103 "2-block transitive" pentagon tilings.

Rice had completed half of a correspondence course in commercial art before she married. Throughout her investigations, she explored how to use pentagonal tilings as grids on which to overlay tessellations of flowers, shells, butterflies and bees.

"Much of Rice’s investigations remain unpublished, in that only the product of her investigations are shown. How she devised these is not generally shown. However, some of her investigations are indeed shown in The Mathematical Gardner, a compilation of articles in honour of the late Martin Gardner, with Doris Schattschneider’s article In Praise of Amateurs (mostly concerning background detail on Rice’s pentagon tiling findings), pages 140–166. Pages 154–155 contain numerous convex pentagon tilings".

Rice's archival fonds are at the University of Calgary Library, Alberta, Canada, in the Eugène Strens Recreational Mathematics Collection.

Four pentagonal tiling classes discovered by Marjorie Rice

Recognition In 1995, at a regional meeting of the Mathematical Association of America held in Los Angeles, Schattschneider convinced Rice and her husband to attend her lecture on Rice's work. Before concluding her talk, Schattschneider introduced Rice. "And everybody in the room . . . gave her a standing ovation."

Rice's papers and materials in support of her mathematical discoveries are preserved at the Eugène Strens Recreational Mathematics Collection at the University of Calgary Library, Alberta, Canada.

Personal life Marjorie Ruth Jeuck married Gilbert Rice in 1945. She had six children, of whom one did not live past infancy.

Rice died July 2, 2017, in San Diego, California.