Please provide formulas, and some examples please for the following.

Ch$\mathrm{.}6-$Discounted Cash Flow $($DCF$)$

Using the financial calculator to include cash flow payments $($PMT$)$

Calculate the PV$,$ FV$,\%$ and number of payments $($N$)$ with recurting cash flows

Definition of "Annuity", how to calculate annuities, examples of annuities