PRACTICAL AND THEORETICAL SYSTEM

OF

ARITHMETIC,

CONTAINING A

NEW SYSTEM OF PROPORTION;

WITH

"THEORETICAL EXPLANATIONS OF ALL THE PRINCIPAL RULES.

BY GEORGE WILLSON.

FIFTH EDITION, REVISED AND CORRECTED.

CANANDAIGUA.

PUBLISHED AND SOLD, WHOLESALE AND RETAIL, BY

C. MORSE.

BOLD ALSO BY F. J. HUNTINGTON & CO., NEW YORK; OLIVER
STEELE, ALBANY; BENNET & BRIGHT, UTICA; AND BY

ENTERED, according to the Act of Congress, in the year 1838, by GEORGE WILLSON, in the Clerk's omce of the District Court of the District of Michigan.