A NEW SYSTEM OF ARITHMETIC, ON AN IMPROVED PLAN: EMBRACING THE RULES OF THREE, SINGLE AND DOUBLE, DIRECT AND INVERSE; CURRENCIES; INTEREST. AND ALL PROPORTIONAL QUESTIONS IN ONE RULE APPLICABLE TO THE WHOLE THE PROCESS GREATLY SIMPLIFIED AND ABRIDGED. BY CHARLES G. BURNHAM, A. M. KEENE, N. H.: PUBLISHED BY S. & G. S. WOODWARD |