The arte of vulgar arithmeticke : both in integers and fractions, deuided into two bookes: whereof the first is called Nomodidactus numerorum, and the second Portus proportionum: with certeine demonstrations, reduced into so plaine and perfect method, as the like hath not hitherto beene published in English. Wherevnto is added a third booke, entituled Musa mercatorum: comprehending all the most necessarie and profitable rules vsed in the trade of merchandise. ... in the forme of a dialogue ... Newly collected, digested, and in some part deuised by a welwiller to the mathematicals.