__Basic operation__

To make a calculation, enter a
formula in the display by using the symbol of numbers, operations and functions
available on the keyboard buttons.

Each button can have up to three symbols, the main symbol is displayed in the center, the
second in the upper left and the third in the upper right. The second or third
symbol is accessed by pressing on « 2ndF » or « 3ndF »before.

The display has a capacity of 19
symbols, but the formula can contain up to 65000. The overrun of the display is
indicated by the color change of the triangles below the display.

Once the formula is complete, press « ENTER
». VFCalc performs the calculation of the formula and displays the result.

If there are errors in the formula,
the cursor moves to the left of the symbol that generates the error and
displays an error message.

To make corrections to the formula,
press the triangles to move the cursor to the desired location. Press « BACK »
to erase the symbol to the left of the cursor. Press « DEL » to erase
the symbol to the right of the cursor. Press a symbol to insert it in the
formula. Once the corrections are completed, press « ENTER »

VFCalc keeps a history of
calculations performed. It is accessed by pressing the history « HIST » (2ndF).

Several settings are available in
the preferences menu. It is accessed by pressing « PREF » (2ndF).