First off, I want to say that I read several related questions about IQ and fluid intelligence here on Stack Community and I need some further clarifications about domain expertise. A few months ago I took Mensa IQ test from its local representative office in my homeland, I wasn't able to make it to the top 2% and gain membership, however, my official overall score was estimated to be 126. Ever since then, I became obsessed with the idea of improving my IQ. I did a research but as I was reading and reading I came to a conclusion that it is virtually impossible to increase one's score, it is, basically, fixed. People on the forum have mentioned couple of times that, although, IQ is fixed and can't be improved by, say, practicing brain games and logical puzzles, one can improve his/her abilities in certain domain and gain expertise by deliberate practice, which, the way I see it, means it is possible to increase your IQ in a particular area. I want to know if mathematics could be regarded as such area and if it does, what are the most efficient techniques to develop it?