A new system of arithmetick, theoretical and practical. Wherein the science of numbers is demonstrated in a regular course from its first principles, thro' all the parts and branches thereof; either known to the ancients, or owing to the improvements of the moderns. The practice and application to the affairs of life and commerce being also fully explained: so as to make the whole a complete system of theory, for the purposes of men of science; and of practice, for men of business