 In the Options menu you can change parameters like calculation mode, precision, etcetera. Selected options are saved on your computer.

## Exchange rates

Convert currencies by pressing `x`. You can reverse the calculation (from foreign currency to base currency) by first pressing `z`. Set base currency with `y`. The up-to-date currency rates are imported when you start the calculator or when you change base currency. The rates are downloaded from the European Central Bank or from Yahoo Finance. ## Hours:minutes:seconds

The stack-calculator lets you easily work with hours:minutes and hours:minutes:seconds (or degrees with minutes and seconds). Use `:` (or more easy `;` ) to enter minutes and an optional second time to enter seconds. E.g. enter `12:53:18` for 12h53m18s (this will be converted to 12.88333). Use Notations, format hms or hm to display and calculate with min/sec.

Use `z` Notation and choose hex, oct or bin to display hexadecimal, octal or binary numbers. Enter hex number by starting with 0x e.g. `0x10` to enter decimal 16. Enter octal numbers with `0o..` and binary numbers with `0b..` This also works with Notation on normal. The number is then directly converted to decimal.

## Fractions

Use `z` Notation fraction to display numbers as fractions. Enter a fraction with `\`, e.g. `3\4`. The maximum number of digits of the denominator is defined by the set precision (Options Precision). See for example how π (pi) is displayed as a fraction depending on the set precision (22\7, 311\99, 355\113, 312689\99532, etc). The entry of fractions also works with other notations. The fraction is then directly converted to the set notation.

## Complex numbers

You can calculate with complex numbers, both in rectangular format (a+bi+) and in polar format (r<φ). Set the right notation (`z`).You can enter complex numbers in the form (a+bi), or [a+bi (the closing bracket can be omitted). For polar notation you enter r<φ, e.g. 5.1<1.2. The angle in radian or degrees (set in `o` Options). By changing the notation you can easily convert polar to/from rectangular. The standard arithmetic operations are supported, but also exponential, logarithmic and trig functions. The result of every calculation is stored in the Last Answers register. So to enter a previously calculated value simply press `l` and select the required value. Last answers are saved on your computer.

## Memory

For most of the calculations the RPN stack is sufficient. But sometimes you want to store (intermediate) results. For this you can use the Memory block. Just press `m` to store the value from the x-stack to the first free memory place. Or use `s` followed by a character to store it on a specific place. Use `r` followed by a character to recall a number. The Memory block is also used for cashflow calculations. All stack values (in RPN-mode), last answers and memories are saved on your computer.

## Finance

You can use the calculator for three types of financial calculations: CAGR (Compound Average Growth Rate), Annuity and Cashflow.

### CAGR

Enter 3 out of 4 variables to calculate the unknown variable.

### Annuity

Enter 3 out of 4 variables to calculate the unknown variable. If you have also given the payment number `x` you can also calculate financial values for that number.

### Cashflow

Use the memory block to store the cashflows, starting at place 0. Take care that cashout values have a negative sign and cashin values a positive sign.

## Constants

Enter physical constants by pressing `g`.

## Conversion

Select unit conversion by pressing `v`.