Almost all normal conversions allow you to calculate values with a precision up to 1000 digits after the comma:
It is also possible to view the result in a scientific form by checking
the Check box called "SCI":
The textfield "Set significant figures" is disabled, if the category that you have choosen does not allow to process digits after the comma:
A special graphical panel can appear, dependent on the actual context. For example, this is the panel for the category called "Queries on a Date":
"Color", ...
and "Spoken Numbers"
etc.