The dozen system
Terry, George S.
The dozen system an easier method of arithmetic [by] George S. Terry. - [1st ed.] - London New York Longmans Green 1941. - 53 (i.e. 63) p. illus., map., tables. 29 cm.
Reproduced from type-written copy. Paged by the dozen system. "Duodecimal protractor reading .002 circle" and table laid in.
41005267
Numeration
QA141 / .T39
511.2
The dozen system an easier method of arithmetic [by] George S. Terry. - [1st ed.] - London New York Longmans Green 1941. - 53 (i.e. 63) p. illus., map., tables. 29 cm.
Reproduced from type-written copy. Paged by the dozen system. "Duodecimal protractor reading .002 circle" and table laid in.
41005267
Numeration
QA141 / .T39
511.2