# Options

Use the "Extras→Options" menu item to set options:

- Background colour for scale factor
  Show evaluation using a colored background. Without this option the evaluation is shown by symbols in the fourth table column.
  - ++
    Very good, scale factor is a power of 2.
  - +
    Good, scale factor is integer.
  - no symbol
    Acceptable, scale factor is a rational number.

The option is used for all following calculations.