Fancy name, but it really just means 'understanding what you are doing'. The term meta-cognition is used by the Singapore Mathematics Framework to mean 'monitoring one's own thinking, self-regulation of learning'

In simpler terms, this can mean letting students come up with their own methods of solving problems, asking with interest how they did it, and helping them recognize any errors in the result themselves.

Bill Jackson wrote an interesting article that discusses the Singapore Math philosophy here