Even if you aren’t in a calculus class, you may find some of the tools in the TI-Nspire Calculator Application menu's Calculus submenu helpful. Using the Numerical Function Minimum tool, you can find the minimum of a function without graphing it. The Sum template finds the sum of a sequence, and the Product template finds the product of a sequence.
To find the numerical derivative at a point, press [MENU]→Calculus→Numerical Derivative at a Point. A wizard automatically starts to help you enter the syntax correctly. On the flip side, the Calculus submenu also has a Numerical Integral command, which uses a template to find the definite integral. (See the second screen.)
The Finance Solver is one of the most versatile tools on the TI-Nspire. In the third screen, the Finance Solver is used to calculate how many years it’d take to save a million dollars at 10 percent interest if you saved $5 a day (a little over 42 years).
In addition, you can create an amortization schedule for a mortgage. And, using the most obscure tool on the TI-Nspire, you can find out how many days are left in the school year with the Days between Dates command.