Calculator settings
Open the Calculator app, tap the Menu icon 
(at the upper-right corner of
the screen) > Settings. You can set Vibrate on tap, Parenthesis color, Operator color, and Answer color.
Open the Calculator app, tap the Menu icon (at the upper-right corner of
the screen) > Settings. You can set Vibrate on tap, Parenthesis color, Operator color, and Answer color.