In 1972, Texas Instruments (TI) entered the electronic calculator market with the introduction of three models.
Also known as the Datamath, it offered four-function, full-floating decimal point with an eight-digit LED display. Also rechargeable it was originally priced at $149.95 when announced in April of that year, but was priced at $119.95 at launch.
Learn more at http://www.datamath.org/BASIC/DATAMATH/ti-2500-1.htm.
Priced at $84.95, it had an 8-digit display with automatic floating decimal and the four basic math functions.
Learn more at http://www.oldcalculatormuseum.com/ti3k.html.
Priced at $99.95, the TI-3500 offered a wider display than the TI-3000 with 10 digits and two sliding switches to select between CHAIN or CONSTANT calculations and to adjust the position of the decimal point.
Learn more at http://datamath.org/Desktop/ti-3500.htm.