How to use "Engineer Notation" (SI Prefixes)?

[rushfan]

On my casio scientific calculator, I can do things like multiplying 5M*1µ to return 5.
When I do the same multiplication in the HP Prime, it returns 5_M*µ.
There should be an easy way to handle SI Prefixes in the CAS.
I've tried using the Prefixes in the Units menu, but I couldn't make it work proper.

The way it work on the casio can be seen here: https://www.youtube.com/watch?v=_1aHyFWdQOs
Here is the multiplication on my casio:


Here is the same multiplication on the HP Prime: