Au contraire, mon frere!

You say "The math question was controversial because it was expressed in language rather than properly written. Divide 100 by 1/2 may mean by .5, in the customary sense of half of one, or it might be an adjective applying the fraction in to 100, and mean 50."

No. The math question was clearly and unambiguously stated, and stating it in math terms would not change it.   You are suggesting that the solver multiply by 1/2 rather than divide, as the problem clearly states: "Take 100 and divide it by 1/2", not "multiply it by 1/2". 1/2 is five tenths. 100 (division sign) .5 is the operation prescribed. Written other ways (shortened) it may be expressed as:

__100__ or __100__   or    __200___
(1/2)       .5          .5) 100      

208 is the answer, and no other.

Frankly, I think the problem as stated was intended as a trap for the inattentive. But if one pays attention, it's clear.

Dave Oesterreich