how to populate datagridview using textbox's data

Question

Say, I need to calculate number of credit card payments, enter data in

1)   Textbox1, enter total credit card balance     
2) Textbox2, enter interest rate
3) Textbox3, enter number of payments

Click a Button to calculate and list number of payments, remaining balance, and
interest accrued display results in the datagridview.

Thanks