Arithmetic without figuring
Subtitle: book of instructions for the equationor, or universal calculator
By: by Walter Hart
Series: Harvard pre-1920 social history/business preservation microfilm project -- 347
Publisher: Equationor Co.
Published: 1892
Place of publication: New York
Language: eng
Number of pages: 24
Subjects: Calculators; Office equipment and supplies
Other titles: Book of instructions for the equationor