![Mashable on Twitter: "Number nostalgia: Why the Texas Instruments graphing calculator ruled classrooms for decades. http://t.co/DeWppVBGKE http://t.co/AcPKEe8YtU" / Twitter Mashable on Twitter: "Number nostalgia: Why the Texas Instruments graphing calculator ruled classrooms for decades. http://t.co/DeWppVBGKE http://t.co/AcPKEe8YtU" / Twitter](https://pbs.twimg.com/media/BpSo_6XIAAAcRL7.jpg)
Mashable on Twitter: "Number nostalgia: Why the Texas Instruments graphing calculator ruled classrooms for decades. http://t.co/DeWppVBGKE http://t.co/AcPKEe8YtU" / Twitter
![File:Texas Instruments TI-1500 Electronic Pocket Calculator With Red LED Display, Circa 1974.jpg - Wikimedia Commons File:Texas Instruments TI-1500 Electronic Pocket Calculator With Red LED Display, Circa 1974.jpg - Wikimedia Commons](https://upload.wikimedia.org/wikipedia/commons/5/56/Texas_Instruments_TI-1500_Electronic_Pocket_Calculator_With_Red_LED_Display%2C_Circa_1974.jpg)
File:Texas Instruments TI-1500 Electronic Pocket Calculator With Red LED Display, Circa 1974.jpg - Wikimedia Commons
Texas Instruments TI-2500 (Datamath) Handheld Electronic Calculator | National Museum of American History
![Texas Instruments Building and future LBJ Freeway in 1959. (Dallas Public Library, 1959) | Texas travel, Dallas fort worth, Old fort Texas Instruments Building and future LBJ Freeway in 1959. (Dallas Public Library, 1959) | Texas travel, Dallas fort worth, Old fort](https://i.pinimg.com/originals/ec/c4/c0/ecc4c0e43c6f0f2d383d0b914946e8b9.jpg)