==External Links==
* [http://www.computinghistory.org.uk/det/22082/Addition-and-Subtraction-1/ Centre for Computing History: Addition and Subtraction 1]
* [https://elisoftware.org/w/index.php/Addition_And_Subtraction_1_(TI99%5C4A,_Cartridge)_Texas_Instruments_-_1981_USA,_Canada_Release Eli's Software Encyclopedia: Addition and Subtraction 1]
* [https://gamefaqs.gamespot.com/ti99/189569-addition-and-subtraction-1/ Game FAQs: Addition and Subtraction 1]
* [https://books.google.com/books?id=eD4EAAAAMBAJ&pg=PA30&lpg=PA30&dq=ti+99+addition+and+subtraction+1&source=bl&ots=8inaXK_nqr&sig=8BZrgHwZFF_Q7dqEda8HEVkWfyg&hl=en&sa=X&ved=2ahUKEwihtcuRlurcAhXk7IMKHUwnCDE4ChDoATAJegQIARAB#v=onepage&q=ti%2099%20addition%20and%20subtraction%201&f=false/ InfoWorld Software Review: Addition and Subtraction 1 (Feb. 8, 1982, pg.30)]
* [https://www.retroplace.com/en/games/7542--addition-and-subtraction-1/ Retroplace: Addition and Subtraction 1]
* [http://www.ti99ers.org/timeline/cartbytitle.html#A TI-99ers On-line User Group: TI-99 Cartridge Listing]
[[Category:1981 1982 Software]]
[[Category:Educational]]
[[Category:Mathematics]]
[[Category:Scott ForesmanMilliken]]
[[Category:Software]]
[[Category:Solid State Software Command Module]]
[[Category:Solid State Speech Synthesizer]]
