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Wolfram|Alpha evaluates

$2\%\%\%/2$

to $1×10^{-6},$

as well as many other online (google) and offline calculators.

My question: Is it really so, and one can represent one millionth as $1\%\%\%$? (Or maybe it is kind of a bug?..)

Thank you for any opinions and suggestions!

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    @RossMillikan: I think we're just giving the same answer from two different perspectives. It's grammatically incorrect but mathematically/syntactically correct.2012-10-25

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Essentially all these interpret $\%$ as multiplication by a factor of $10^{-2}$ since $2 \% = 0.02$. Hence, $2 \% \% = (0.02) \% = 0.0002 = 2 \times 10^{-4}$

EDIT

I am not sure whether it is an abuse of notation. The way I interpret $\%$ is $\%: x \to \dfrac{x}{100}$. Hence, in my understanding it would be completely valid to think of $\% \%$ as a composition of the function $\%$ twice.

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    **EDIT** makes it clear.2012-10-26
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It is mathematically correct, but generally you shouldn't write it (for the same reason you shouldn't write "0.000002 million" in place of 2).

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    We often use "$.3$ million" instead of "three hundred thousand" (for example). It's certainly *goofy* to use "$.000002$ million" instead of just "$2$", but it's certainly acceptable.2012-10-25
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This is not correct usage. While "$2\%$ of $150$" is the same as $\frac2{100}\cdot 150=3$, this does not mean that we are allowed to abuse the percent notation like this with repeated percents.

One would also not say that $1^{\circ\circ}=\frac\pi{180}^\circ=\frac{\pi^2}{180^2}$.

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    @OlegTra$k$hman: But is it a bug? What I wrote was my personal understanding of the matter ("guts feeling"). Meanwhile I see that "even" Wikipedia does not support my view. It seems I need a refence, probably from outside math usage. ("We" mathematicians don't use percent anyway, it's just courtesy for them bankers and bookies ;) )2012-10-25