It all about context really and what lies in the heart. One stumbles upon a kid doing some yoga moves he learned from his gym teacher, probably not a lot of harm there, he’ probably just stretching as one poster put it! Doing yoga and incorporating TM or hindu/bhuddist chants, quite another issue again, which the pastor mentioned in the posting was trying to warn against.
Similarly with math, it helps me with my checkbook as well though I often fret as to how little my account contains after expenses and all the freaking taxes we have to pay!
Then there are the Christians who practice numerology and have received secret messages from God about 666.