III · Science
Math
Subjects
Mathematics, problems, exercises, etc. · Mathematics, study and teaching (elementary) · Mathematical ability · Mathematics · Study and teaching (Primary) · Activity programs
Language
ENG




![Cover of [William Wheeler Hubbell, authorized to apply for patents.] by United States. Congress. Senate. Committee on Patents](https://covers.openlibrary.org/b/id/10200621-M.jpg)
