Quick switch between number format and exact/approximate results

[qwezxcrty]

When I'm using a CASIO calculator, there is a extremely useful feature. That is we go to the history, select a output, and press the exponential key, we can toggle between scientific notation of the number or the number format. This can make small numbers much more readable, so that I don't need to count the zeros if I have a number like 1e-5. The fraction key also works similarly by switching between exact forms and approximate results.

Is there anyway to implement this, such as by user keyboard? Although less ideal, the toggled output can be shown else where, if changing directly the display in the history is not possible.