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

[Joe Horn]

(05-16-2017 02:52 AM)rushfan Wrote:  Yes, that makes sense, but they still don't work in CAS mode.
I have tried them in Home and using USIMPLIFY, and it worked, in some cases.
For example, if I input USIMPLIFY(5_M*μ*s²) I will receive an "Error: bad argument type".
Yet, USIMPLIFY(5_Ms*1_μs), which is the same thing, the same unit and the same physical quantity, will work.

That's because the former expression (5_M*μ*s²) is not syntactically an expression of units. It is the product of three things, none of which are valid units. 5_M is not a unit. μ is not a unit. s² is not a unit. You can't USIMPLIFY something which is neither a unit nor a valid algebraic combination of units.

The latter expression (5_Ms*1_μs) DOES work because it's a syntactically valid product of two valid units. It is NOT "the same thing" as the former expression at all. 5_Ms is a unit. 1_μs is a unit. They can be validly multiplied together to form a unit, which can therefore be USIMPLIFY'd.