Visitors were fixated as Yeh Kuoyi swiftly twisted puzzle-like plastic pieces into different shapes at the Taiwan pavilion, during the 14th China Beijing International Cultural and Creative Industry Expo in late May.

Yeh, who's from Taiwan, invented the toys over two decades ago to help children appreciate math.

He has attended similar exhibitions on the mainland dozens of times over the past decade, he says.

"The mainland market is really big, so we come here a lot," Yeh says.

"We get good feedback. We've enjoyed steady growth from the mainland in recent years."

His toys are used by many mainland kindergartens and primary schools.

Yeh has also played a leading role in organizing other Taiwan exhibitors to participate in the Beijing expo.