Functional Overview

This basic business calculator displays percents and some simple bar graphs without additional keystrokes. In addition to arithmetic operations, the app features percent change (for finding the percent increase or decrease from one number to another), a margin mode (cost-sell-profit-margin), one-touch tip and tax functions, and a visible memory. The calculator displays numbers less than 1012 (1 trillion) and handles the number of decimal places (up to six) automatically. A rounding option is available for 2 decimal places in calculations.

Basic Input and Output

The Percent Calculator keypad adjusts its keys in context with calculations. Button labels are often dimmed or hidden when not available, but appear when needed. This makes efficient use of space, maintains large keys and reduces clutter.

Continuous addition and subtraction percentages are provided, but to avoid ambiguity with order of operations, the equals sign is may be required before multiplication or division.

The memory is controlled with 3 keys: [M+] (memory plus) is used to add a value to the memory, allowing the memory to keep a cumulative total. If a number should be subtracted from the memory total, simply make it negative by using the Change Sign key [±]. The [RCL] key (memory recall) pastes the memory value into the equation, either as the first or second entry. The [MC] button (memory clear) deletes the current memory value and resets the memory. These memory keys operate independently of the main calculations. The memory can be cleared anytime without affecting the main functions.

Touching the display area reveals a 16 line review screen. It is possible to switch back and forth between views without affecting the state of calculation (to check on a previous number, for example). From the review screen, an info button provided instructions for taking screen shots, and an “Edit” button launches a 100+ line scrolling list compatible with cut, copy, and paste. There are three separate list memories that can be used to store results.

Visualizer Bars

The visualizer bars appear under the main result display.

Division is represented by the first number over the second number, making it easy to see if the result is greater than one or less than one, a fundamental determination in division. The magnitude of the difference indicates how large or small the result is.

Multiplication of numbers greater than one: Gray bars represent the result, and the narrower green or red bars indicate the input numbers (see how many times they fit into the result).

Multiplication of numbers less than one: The single gray bar represents one of the inputs, and the green bar represents the percentage result of the multiplication.

Feel free to experiment with calculations to get comfortable with the visualizer bars. They are a powerful visual check for most computations.

The TIP/A% button

This simple TIP feature adds a 10%, 12%, 15%, 18%, 20%, 22% or 25% tip to a first number entry or a result. Arrow buttons appear to adjust the tip amount, and the selected value is retained and used the next time the button is pressed. Custom values can be loaded after a [C] (clear).

Similarly, the A% option allows the same button to be used for general percents (including one-button discounts if a negative value is set). The arrow buttons will index +/- 1 or +/-5, as set from the home “info” screen.

The tax button

This function was created to allow one-touch tax calculations. It also includes a minus tax option (e.g. For a certain final price, tax included, what should the selling price be?). The main info area has options for tax splitting (e.g. district and state taxes in California or PST and GST in Canada).

The Clear button

This large red Clear button often becomes a “clear entry” button, [CE], allowing re-entry if necessary. Otherwise, Clear resets the display so that a new calculation can begin. The visible memory and the review list are not affected (they are cleared separately with their own buttons).

The Sell - Cost - Profit - Margin function

This function is available on start-up or following a clear [C] by pressing the lower right [margin] button. Once in this mode, enter a value and press one of the cost/sell/profit/margin buttons. Then enter the second number and its button. Results are displayed and another number can be entered. Specify sell (and not cost), and cost adjusts; otherwise, sell adjusts. Toggle between margin and markup. Results can be scaled using the Q1 and Q2 values (e.g. box and order quantities). If the margin bump buttons are used, the adjusted entry is indicated with stars in the review listing. Margin bump buttons allow “what if” analyses.

An optional sell* mode displays selling price with tax (especially for GST and VAT taxes).

Saving Results

Screen shots are saved in the Photos application (under albums “Camera Roll” on the iPhone and “Saved Photos” on the iPod touch). These can be viewed and emailed from within the Photos app.

The [Edit] button transforms the displayed list into a large text view that can be edited and is compatible with copy-cut-paste. Edited lists can be saved or recalled be accessing 3 dedicated list memories. Entire lists or segments can be copied and pasted into other applications (e.g. email).

Visualizer Bars:

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