Originally Posted By: ColinsMum
DS8, doing an ALEKS topic on equations involving logarithms, gets a "Your answer is incorrect", which it is, because his calculation has given him a spurious solution (one that would have made the original equation involve the logarithm of a negative number), and he has entered it without noticing.

Me, perhaps slightly patronisingly: Remember, you can't take the logarithm of a negative number.

DS8, more patronisingly: Well, you can in fact, it's just that the answer is complex.

He has met Euler's identity, but we're confident that nobody, and no book, has ever talked to him about anything closer to this statement than that.

How's that for a wibble-brag?!

Off to google what your kid actually did.  I had just used reading context clues to assume he made a math problem that needed negative numbers which mixed up two lessons in a way they hadn't taught yet.  

Ah, the base of an exponent.  
Your kids got a great number sense!

Mr google tells me that's part of number theory which AOPS says is appropriate for 6-9th grade if they've already finished Algebra 1.  Um.. Not a  bad "stumble upon" for an eight year old to deduce.
Youth lives by personality, age lives by calculation. -- Aristotle on a calendar