# Display

The calculator display has a number of built-in features, including the ability to show numbers in different modes as defined in the Mode dialog tab, and in different decimal formats. It can also display arrays of numbers or matrices, which is further explained in the Matrix/Array Functions section.

## Setting the Display Options

Using the Display page of the Options dialog, you can select the type of decimal display - normal (or floating point), fixed point, scientific, or engineering. You can also choose the number of digits, which for scientific means the number of significant figures, and in fixed point means the number of digits after the decimal point.

If you compute a number in fixed point display the value is not rounded at each step (i.e. numbers are internally stored to the maximum precision available). This can occasionally be a problem in financial calculations if the existence of the extra precision is overlooked. Be careful not to increase the number of digits too far if the display font is large, otherwise there is a danger that significant digits (or worse, the exponent!) may be overlooked, particularly in scientific or exponent display mode. Digits which are not visible because they lie outside the display area can be seen by using the cursor to increase the size of the calculator. The display re-sizes itself automatically when the calculator window is re-sized. (On some handheld devices it is not possible to increase the size of the display in this way).

You can choose the font, font colour and background colour. Again, care is needed when changing font, as too large a font at higher precision may result in digits falling outside the boundaries of the display. On certain devices with limited screen area, such as handheld computers, reducing the font size may be needed to make all of the displayed number visible.

### Normal Display Format

This is effectively floating point, until the number is too large or too small to display as a floating point number given the size of the display, at which point the number is presented using Scientific format (i.e. as exponent and mantissa).

For floating point numbers, the Digits edit box specifies the maximum total number of digits displayed.

### Fixed Display Format

The number is displayed with a fixed number of decimal places, determined by the value in the Digits edit box.

### Scientific Display Format

In Scientific format a number is displayed as an exponent and a mantissa in the range 1.0 to 9.999 (recurring, to the available number of digits). (i.e. as exponent and mantissa). The number of significant digits is specified by the Digits edit box.

### Engineering Display Format

Engineering display format is the same as Scientific format except the mantissa is adjusted so that the exponent is always a multiple of three. e.g. 1.234e5 is displayed as "123.4e3". The number of significant digits is specified by the Digits edit box.
The statistics mode is equivalent to decimal mode for the purposes of number display.

### Display in different modes

When the calculator is in financial number mode, the display format is fixed point with two decimal places.

Angle and Time modes cause the number to be displayed as a sexagesimal number.

### Decimal Symbol

In most English-speaking countries the decimal symbol is the full stop. But in many countries a comma is used and the Decimal Symbol drop down box allows you to select the appropriate one. You can also use a space character. When the calculator is first run the decimal symbol will be picked up from the locale you have set for your computer, but this can be overridden. If you change your locale, but have already run the calculator on this computer, or have run an earlier version, you will need to change it manually.

### Digit grouping

Groups of three digits, i.e. thousands, can be separated using the Digit Group drop down, e.g. "10000.00" can be made to display as "10,000.00". A comma, full stop or space character can be used to separate the groups of digits, or the feature can be disabled by selecting "no".

### Display of non decimal numbers

For Binary, Octal, Hexadecimal and Base-N modes, the number is displayed in the appropriate format. Fractional parts of numbers are not displayed in these modes. The interpretation of signed numbers is determined by the state of the Base Signed check box. If checked, negative numbers are displayed as signed numbers. If not checked, numbers are displayed as if they were unsigned.

## Other Display Properties

Numbers can be Left, Centre or Right justified within the display (or display cell in array mode).

The colour of the cell background can be changed using the colour well (another two on the matrix page are used in array mode). Click on the colour well with the mouse to obtain the colour selection dialog. The foreground colour is changed as part of the Font dialog which is obtained by pressing the Font button. This allows the size, type and colour of the font used to be changed.

The "2's comp" setting is used to control the way in which BaseN, Octal, Binary and Hexadecimal numbers are represented, and is described in more detail in that section.

For information on change the appearance of the grid for arrays, see the arrays and matrices section.