The principles of arithmetick : with helpfull observations, making the entrance easie, and the practice pleasant: teaching the five ordinary parts of arithmetick, the usuall way: the performance of multiplication and division, onely by addition and subraction: with new and notable abridgments: rules of practice, with extraordinarie helps: and therein, some excellent observations, for the easie casting up of interest. The doctrine of fractions, the foure rules of arithmetick: recreations extraordinary; or the easie performance of (seeming) impossibilities. By William Webster.