Four scientific calculators (using binary numbers internally):

• pycalc_light (light theme)
• pycalc_dark (dark theme)
• pycalc_lcars (LCARS theme)
• pycalc_units (converts from US units to metric units, e.g. to l, m, m2, and kg)

There is also pycalc_desk, a four-function calculator using decimal internally, based on Python's decimal module.

The decimal calculator is useful to avoid the rounding errors of the binary calculators due to their decimal➜binary➜decimal conversions, which is better for e.g. financial calculations. It also has memory (M+ to add, MR to recall value, AC to clear) and the comma is used as a decimal separator in results.

For the unit converter, just attach the unit to the numerical value. E.g. to convert 1.5 quarts to liters, use "1.5_qt". If you would like to divide by a value, put the number and unit in parentheses, e.g. "(1.5_qt)", otherwise the result will be wrong!

The scientific calculators work the same as the Python math module in interactive mode:

• They use binary numbers internally, not decimal, so it has the usual rounding errors when comparing its results to a decimal calculator, e.g. "0.1 + 0.2" does not evaluate to exactly 0.3.
• The green buttons are for base conversion (hex/oct/bin) and entering numbers in other bases (0x, 0o, 0b).
• The trigonometric functions all input or output angles in rad of course, so use "rad" and "deg" to convert accordingly.
• "fah" and "cel" are Fahrenheit/Celsius conversion. E.g. "cel(100)" converts 100°F to Celsius. They also demonstrate how to add custom functions to the calculator.
• The imaginary unit j has a button. Note that not all Python math functions work with imaginary numbers, e.g. "exp" does not but "**2" does. Also "abs" is useful for imaginary numbers, e.g. "abs(3+4j)" = 5.
• SCI displays the result in scientific notation, pressing "=" switches back to normal display.
• The "e" button has multiple functions: As a variable, it is 2.718... (see table below); it is also used for entering numbers in scientific notation, e.g. 2e18; and it is the hex digit that equals 14.
• You can get asin, acos, and atan by first typing "a" from the hex block and then sin/cos/tan.

The hex buttons (a to f) and "j" can also be used as these predefined variables (a, b) or constants:

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Public Domain / CC0

• Digital-7 Mono by Sizenko Alexander
• Antonio by Vernon Adams
• Fixedsys Excelsior 2.00 by Darien Valentine
• OCRA by Matthew Skala