Alvin - Construction Master - Pro Calculator - 4056 - The Alvin Construction Master Pro Calculator is a feet-inch-fraction calculator that features a broad range of nearly automatic construction/math problem solutions. From its single key solutions to arc length, circumference, circle area, board feet conversions, and weight-per-volume conversions, this popular calculator works in most common construction or building dimensional formats. It adds, subtracts, multiplies, and divides in feet-inch-fractions, decimal feet (10ths, 100ths), inches, fractions, decimal inches, yards, meters, centimeters, millimeters, and square and cubic dimensions. Plus, it converts to and from any dimensional format. Model CA224 automatically finds lengths of rafters, regular (45) and irregular (non-45) hips, valleys and jacks, stair stringers, angle of incline, number of risers and treads for any landing-to-landing height, plus riser height and tread width. Covers practically any construction, building, or remodeling application. Features paperless tape for reviewing past 20 entries. Model CA227 features advanced dedicated key functions for blocks, roof areas, and footings. Enhanced stair, rafter, rake wall, and circular cone functions. Both models include easy-to-follow pocket reference guides in English and Spanish, English and Spanish How-To CD and user guides, long-life batteries, and a full one-year limited warranty. Alvin is one of the primary sources for drafting supplies and drawing equipment in the country. Creative Coldsnow is a pround retailer of Alvin graphic arts, drafting and fine arts products.