The story
Calculated Industries' first entry into the calculator business came in the later 1970s with The Loan Arranger. It was one of the first Real Estate calculators to simplify the process of calculating a loan payment, breaking away from the traditional financial key labeling of “I”, “PV”, “FV” to more clearly labeled function keys. It also predated the well-known HP12c financial calculator.
With the success of The Loan Arranger the Alexander brothers tried a few other specialty calculators such as the GradeMatic calculator which helped teachers compute student grades, and the Graphic Arts Master. However, the real success of the company came in 1985 with the creation of the Construction Master. According to Mark Bollman, a mathematics and calculator historian and associate professor of mathematics at Albion College, the "Construction Master is the first in a long and profitable line of CI construction calculators". The Construction Master came preprogrammed with common construction calculations, and was a significant move forward for those dealing with construction math (such as angles, stairs, roofing math, pitch, rise, run, etc.). Fine Homebuilding magazine described the calculator as a noteworthy contribution to those in the construction field in an article based on the 25 Years of Milestones that help shape the homebuilding industry. The success of the Construction Master calculator gave the company drive to focus on more construction-related products and has since produced related calculators such as the ElectriCalc, Material Estimator, Heavy Calc, Project Calc, and most recently a Pipe Trades calculator.
From Wikipedia’s article on Calculated Industries, shared under CC BY-SA 4.0.3