The latest release of the online scientific calculator includes a new functionality: The preferences window. Here you can set the display format for the calculator results. This article gives a bit more information on how the calculator stores numbers internally, it’s precision limitations and explains how to use this new feature.

The prefs key

The preferences of the scientific calculator can be displayed and changed by pressing the prefs key:

A small dialog opens. It shows the current display preferences for the results. If you are accessing this feature for the first time, the values displayed and currently in use are the calculator’s default values: rounding decimals=9, notation=float. When you change the options from this window, the new values are saved for the next time you use the calculator from the same computer, regardless of which browser you use.

Your changes will be saved when you press ‘Apply’ or “OK’. The ‘Apply’ button applies the changes without closing the window. The ‘OK’ button applies the changes and also closes the window. Pressing the ‘Cancel’ button reverts to the previous values and closes the preferences dialog.

The Calculator Preferences Window

The preferences window contains two parameters, the ‘rounding decimals‘ field, where you can specify any number between 0 and 16, and the notation option that you can set to ‘float‘, ‘fixed‘, ‘scientific‘ or ‘engineering‘.

The Rounding Decimals field

Here you specify the maximum number of digits to display after the decimal point. The result is rounded.

It’s important to know that regardless of your display preferences, the calculator stores it’s results internally always maintaining the maximum possible precision. Here you can only change the way the results are displayed to you.

As an example, consider the result of the square root of 2:

If rounding decimals is 9 (and the notation is set to float) the result of sqrt(2) is displayed as 1.414213562, with 9 digits after the floating point

If rounding decimals is 6, the result displayed is 1.414214, only 6 figures after the decimal point. Note the rounding of the number.

If you are only interested in the integer portion, you can set the number of digits after the decimal point to 0, which will display the result as 1. As mentioned above, the value stored internally doesn’t change, it’s only the way the value is displayed ot you that changes. Take a look at the picture below: