Mathematical Treasure: Boole Senior Blocks

Peggy Aldrich Kidwell (National Museum of American History, Smithsonian Institution)

Boole Senior Blocks, geometry learning toy, circa 1935.

Apparatus for Teaching Young Children Mathematics, circa 1935, Smithsonian Institution negative number NMAH-AHB2016q012847

From at least the 19th century, educators have thought that playing with specially designed blocks would give children a tangible sense of mathematical relationships. The San Diego, California, teacher Ethel Dummer Mintzer (1895–1938) designed this set of flat wooden pieces to provide the experience of handling simple geometric shapes. A complete set would include one hundred forty-four blocks: right isosceles triangles in five sizes, squares in three sizes, rectangles in six sizes, and parallelograms in three sizes. Several blocks are missing from this set. The blocks are arranged in two layers on specially printed square sheets of paper and stored in a box with two bases and two lids.

Paper sheets describe possible uses of the blocks. Ideas include making patterns from given sets of blocks, representing equal fractions, rearranging blocks to form figures of equal area, and defining areas. Other sheets concern the Pythagorean Theorem, a binomial expansion, and multiplying fractions. Mintzer copyrighted the set in 1933.

The blocks are named for Mary Everest Boole (1832–1916), a British educator also known as the wife of the logician George Boole and the mother of the geometer Alicia Boole Stott. This particular example was owned by Carol B. McCamman, who taught mathematics at Coolidge High School in Washington, DC. The donor, Florence Fasanelli, taught mathematics at Sidwell Friends School in Washington. McCamman gave Fasanelli the Boole blocks in 1974 as a baby present for her daughter Antonia.

This is one of a group of objects in the collections of the National Museum of American History that were used by girls and women in mathematics education. The group may be viewed at

Index of Mathematical Treasures

Index of Mathematical Objects