"Jerry W. Lewis" wrote:
A more direct confirmation of Martin's claim is
Sub tryit()
Dim x As Double
x = 2# ^ 1023
MsgBox x * x / x
End Sub
If the expression x*x/x were not evaluated in 10-byte
registers, the calculation would necessarily overflow.

That demonstrates that VBA __sometimes__ relies on the 80-bit
FP registers. I wanted to confirm that that explains why my
computation of the average, ergo the variance and standard
deviation, is "exact" to 64 bits, whereas the computation by
AVERAGE() is not. To do that, I believe my recursive example
(or any other way to thwart VBA optimization) was necessary
to prove that point. This is what judges refer to as an argument
"on point".

It only works with inline expressions involving explicitly
declared Double's and using only the basic 4 arithmetic
operations.

Thanks for the insight.

Question: Does this work on non-Intel processors under
Windows or on a Mac?

Since the (2006) Mac uses Intel processors, the question is
moot :-). Just kidding ....

A Google search provides some answers or hints. But since
I cannot confirm the information, I don't want to "speculate"
here.