Datamath TI-2500-II Electronic Calculator, circa 1974

The Texas Instruments TI-2500 "Datamath" was TI's first electronic calculator and one of the most important consumer calculators of the 1970s. Produced beginning in 1972, the Datamath made complicated calculations accessible to many people. Because of the Datamath's popularity and ease of use, electronic calculators began to replace the heavy mechanical adding machines previously used in small businesses.