Tells the story of how ordinary people in eighteenth-century Britain learned and applied popular practical mathematics to weighing and measuring, business, agriculture, surveying, and navigation. The annual almanac 'Poor Robin'--first published in 1663 and outliving its original creator to last until 1828--supplied the data everyone needed about the coming year's tides, equinoxes, and astronomical events. Poor Robin of Saffron Walden, a fantastical figure in British popular culture from the Restoration to the end of the Georgian period, also provided arithmetical tips and tricks as well as subversive spoof astrology and political satire.