These feet-inch-fraction calculators feature 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 and will save time and money. 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 easyto- 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.