She published two books on
arithmetic: • Her first published book is entitled
Tyrocinio aritmético (1738), From a mathematical point of view, the book is eminently practical and written in a fresh and supple language. A great number or examples based on real cases are given to the reader. Thus, one can learn directly the four rules of arithmetic: addition, subtraction, multiplication, and division. In addition, the examples covered in this book indicate that she had precise knowledge of length, weight, and currency units that were used to perform the daily trade activities in the 18th century. As the Dominican priest Pedro Martínez, a friend and collaborator of Maria Andresa, revealed in the review of the book,
"her aim, in this brief piece of work, is to bring the education to the many who have no means to achieve it". Thus, according to her professional profile, Maria Andresa Casamayor is to be commended for her unusually great arithmetic ability and deep concern for education. •
El para sí solo, her second book, is a 109-page unpublished manuscript on advanced arithmetic. She wrote under a male pseudonym, her nom de plume being Casandro Mamés de La Marca y Araioa. This name was a perfect anagram formed by rearranging all the letters that compose her own name, Maria Andresa Casamayor de La Coma. Oddly enough, there is a name spelling mistake in the source of this information, a quotation from the "New Bibliography of Aragonese Writers", (
Spanish: Biblioteca nueva de los escritores aragoneses) by Félix Latassa. In Latassa's catalogue, Maria Andresa is listed under the name of "Maria Andrea". Following Latassa, the name Maria Andrea is still used today. However, according to the baptismal certificate, she was named Maria Andresa. In the Tyrocinio, Casandro claimed to be a "disciple of the Piarist School" (
Spanish: Escuela Pía) and dedicated the book to the same school, "Escuela Pía del Colegio de Santo Tomás de Zaragoza". ==Girls' school teacher==