scientific calculator

NHN-1 is a free advanced engineering and scientific calculator with a transparent widget that has fractions and percentage:

•A resizeable widget with arithmetic, percentage button, and fractions.
•Expression (formula) based input.
•Fraction input and output with conversion to proper fraction, mixed fraction and decimal. Even the quadratic or cubic root functions, for instance, will return fractions when the answer can be written as a fraction.
•Full history with buttons that load old results, in case you need to start over from a previous point.
•Unlimited memory slots that can be named and are always displayed on screen.
•Multiple input fields except on small phones. This let's you do short side calculations without losing your place.
•Pre-packaged functions for quadratic equations as well as many geometric formulae.
•Buttons that store user defined functions that are created by binding an argument to a binary operator.
•Visualization of multivalued complex functions (roots, inverse trigonometric, logarithm)
•Visualization of quadratic and cubic functions
•Visualization of angles returned from inverse trigonometric functions.
•Complex numbers are very easy to work with, and all functions work with complex numbers where they are defined (inverse hyperbolic cosine, for instance).
•There is a fourth layout for small phones that is not shown in the screen shots.
•A unit conversion utility that lets you build arbitrary composite units. Conversion factors are written to the history, so you can bind the factor with multiplication to do the same conversion many times.


The layouts are designed to be ergonomic for each of four device sizes in portrait and landscape. Here are some examples of what we've done to make the calculator easy and speedy to work with:
•On small tablets in landscape, the keys are split so you can operate the calculator with two thumbs.
•On small phones, the numeric keypad is right under your thumb when holding the device with one hand.
•Square root, square, inverse and negation are all close to the numeric keypad.
•On small tablets, the long "NHN-1" button is a gesture recognizer that lets you scroll the six input fields with your left thumb. That way you don't have to let go of the device with your right hand to click an input field.