2 Vintage Math Books Plane Trigonometry Key to Complete Arithmetic Gilt Script

2 vintage mathematics books Hardcover Please view all photos and read condition descriptions No returns 1) Plane Trigonometry By Edward R. Robbins Dark green Published by The American Book Company 1937 edition Illustrations (diagrams and charts) Answer key in back 168 pages plus index Good preowned condition Some cover wear Overall aging/yellowing with a lot inside covers Staining on back cover and to top of front cover 2) Key to Complete Arithmetic Part of Greenleaf's Mathematical Series Based upon the works of Benjamin Greenleaf, A.M. Published by Leach, Shewell & Sanborn 1896 edition 328 pages Very nice preowned condition Some cover wear Light aging/yellowing 1 lb 12 oz