Try to pose math problems that are applicable to real-life situations or games. For geometry problems this is usually pretty easy since they lend themselves to visuals. For algebra, use scenarios in which a person would have to figure an unknown quantity given some other information. The more they can conceptualize it, the more motivated they will be to learn it. Then you can get them to solve abstract problems.
I always found that leading a topic with abstractions just led to people tuning out (except for the mathematically curious students.)