The Calculator has edit function, also has Error and Parenthesis level display function.
Use memory function, make it easy to enter similar expression again and again!

This application is best when:
-Enter a long long expression.
-Enter a expression contains many parentheses.
-Check entered expression after calculating.

Feature
-Edit expression
--Move cursor with cursor key.
--Move cursor by single tap.
--Delete a character with DEL or BS key.
--Scroll expression.

-Error display
--Show error in expression by red wavy underline.

-Parentheses level display
--Show parentheses level by colorful underline.
--Easy find lack or too many parentheses.

-Key assistance
--Show enterable key by key brightness.

-Memory function
--10 memory buttons.(3 buttons on screen, other buttons appear by scroll)
--To drag expression or answer to memory button, memorize it.

-History function
--Record 40 histories.