The Real Number

This application is a 2 line display scientific calculator.
It is realization of my ideal scientific calculator app as tool used by engineers, scientists and science students.
It equips User Interface suitable for Touchscreen. (Direct touch to displayed formula or number works modification or input.)

(Spec)
・4 independent Scientific Calculator sheets. 20 past formulas are memorized in each calculators.
・Function input order is same as formula, like a general scientific calculator, except for parenthesis. From input like Reverse Polish Notation, parenthesis are automatically complemented.
・Improper fraction, mixed fraction, number with square root or π, recurring decimal, can be used in calculation and result.
(The process is simplified and lightened, not Computer algebra system.)
・Internal calculation: 16-digit decimal or fraction or irrational number, independently developed (Not binary floating/double)
・Symbol in number showing whether accurate or rounded. Separators into decimal part.
・More accurate mode to auto extend up to 34-digit decimal in addition, subtraction, multiplication, and division.
・27 memories. The memory can hold not only numeric but also formula.
・SI prefixes can be inputted and displayed in result.
・Copy/paste function of displaying numerical, displaying formula, and held past executed formulas.
・Calculation of formula in Clipboard and appending the result to it.
・Number input and correction by direct touch action to the digit you want to change.
Specifying a function to change/ changing displayed formula and displayed part of formula by direct touch action.
・At the pressed moment of the key, the key function comes display. (Not the released moment.)
・35 constants (CODATA2018) and Golden Number.
・Display number length is selected from 10/14-digit depending on screen size.
・2 sheets can be parallelly shown and operated if screen size is larger.
・Automatic save of the calculation state at the application termination.
・Whole initializing. Or returning to the state at the time application started.
・Selectable decimal point/separator character(5) and separator position(4), and number character(19).
・Configurable rounding location and rounding way.
・Degree/minute/second, radian, gradian can be used as angle units.
・Dark theme(Android10)