"It's important to know your own balance," Chuck says.

To Chuck, the most important part of tai chi is to understand the principles of yin and yang. "That's where balance comes into play, with balancing one part of your life with another," Chuck says.

But it's not just black and white, he says. Balancing yin and yang means being in tune with everything around oneself, including work, health, family and school, says Chuck.

The Sunnyvale realtor began studying tai chi along with his brother John when they lived in Wan Ji, China as young boys. Their grandfather would not let them study kung fu because he was afraid they would get in with the wrong crowd, so they learned tai chi.

Chuck arrived in the United States in 1962 at the age of 9 and continued to study tai chi with teachers in Chinatown in San Francisco. "Staying in Chinatown kept the tai chi dream alive for me." Chuck says.

Chuck came to Sunnyvale in 1973, when his father asked him to help maintain a family-owned nursery on Mary Avenue. "Back then there were only orchards or flower growers," he says.

Chuck continued to practice tai chi in Sunnyvale and held National Grand Champion status from 1989 to 1991.

He founded the Sunnyvale Tai Chi Academy. "Most of my students are engineers, but they're not just here to get away from their day jobs," Chuck says.

Chuck has taught classes at Stanford and other community classes.

Tai chi classes have sprung up around the Bay Area but most concentrate only on maintaining harmony within the body instead of studying all aspects of tai chi, Chuck says.

Chuck teaches tai chi as a martial art, not as an exercise class.

"The idea of tai chi is using as little force as possible. It's not an easy class, and we do sweat a lot," Chuck says.

The practice of tai chi can help one to find physical and mental balance, he says. "By putting weight on one leg and consciously shifting your weight back and forth, we find physical balance."

But through quiet warm-ups or standing meditation, Chuck teaches his students to relax their minds and focus, while practicing tai chi or even in the outside world to achieve mental balance.

The current class meets at the community center or Ponderosa Park. Chuck hopes to use the new senior center.

He says that teaching has helped him learn more about tai chi than anything he has studied. "The good part about teaching is that it teaches me the fundamentals that I might have forgotten," Chuck says. "Students ask me questions and it forces me to think about what I'm doing. I have to go back to the beginning, to the basics for myself to help them."

Each form of tai chi he teaches requires balance and concentration, Chuck says.

He emphasizes tui shou, known in the West as "pushing hands."

The concept is based on the idea of developing "listening jin," or the ability to understand your opponent's intentions as soon as you make contact with his or her body. "It requires you to be gentle so you can neutralize and redirect your opponent's force," Chuck says.

Recently, four of Chuck's students returned from the West Regional Chinese Martial Arts Tournament in Berkeley with a gold medal in tui shou.

From studying as a young boy in China to teaching his students in Sunnyvale, Chuck says he has found balance through the art of tai chi. "I really feel like I've come full circle," Chuck says.