Students in MATH 1110 will typically be going on to MATH 1180 (for eventual calculus) or MATH 2000 (brief calculus). The TI-83 (not Plus), TI-86, TI-92 and the TI-92 Plus are no longer manufactured.
Apple's Calculator app does more than help you calculate tips. With the latest OSes, it launches on iPad and lets you create a Math Note for more complex problems, among other things.
The watches' calculator function can add, subtract, multiply, and divide up to eight digits. As for watch functions, you get dual time, an alarm, stopwatch functionality, ...