Calculated Industries Tradesman Calc Trades Math and Conversion Calculator. The Tradesman Calc is specifically designed to be useful in virtually any skilled trade requiring applied math skills. • Enter and solve ratios and proportions. • Enter math equations using order of operations. • Work with exponents. • Solve dimensional math problems and convert between US and metric dimensional math units. • Work in Architectural (1/4 inch) fractions proper fractions (2/3) mixed number fractions (1 2/3) and improper fractions (5/3). Safety Data Sheet. • Sold as 1 Each.