Yes, NTS has a calculator. To access the calculator, press the "F10" key on the keyboard. The function keys are located at the top of your keyboard.
The calculator is a 4-function calculator with the standard memory function. The M+/M- keys add/subtract from memory. MR recalls the amount in memory. MC clears the memory. The C button resets the calculator amount to zero, but does not change the amount in memory. To close the calculator, click the 'X' button in the upper right corner or click back anywhere on the NTS window in the background.
The calculator rounds all amounts to the nearest penny. Use the mouse or the keyboard to enter amounts and make calculations.