I recently got the Ti-89 Titanium calculator after a lot of people recommended it to me but after receiving it in the mail, I realized I had no idea how to use it. Its so complicated, I don't understand most of the calculator language/functions. So I came to Khan to find a how to calculator video but there isn't any calculator programs on Khan. Calculators are a key part of doing math so please make a video on how to use/understand calculators/add programs/make programs for the calculators! Even calculator program recommendations for SAT.