In order to facilitate the use of a
finger to enter digits, the 'Big Button' mode was
created. This mode changes the screen layout from 6 buttons wide x 5
buttons high (30 buttons) to 5 wide x 4 high (20 buttons).
Tapping
the 'Down' button will enter 'Big Button' mode (on the right, below), while tapping
the 'Up' button will return to the normal button mode.