A wrong answer used to mean extra work with a pen. In many Chinese classrooms, students copied the missed question into a notebook, one problem at a time. That notebook had a name: the wrong-answer book. The habit now has a machine.
The machine is a small printer. It copies the questions a student got wrong, so nobody has to write them out by hand. By the end of 2025, more than 18 million of these smart printers had been shipped worldwide in a single year, People's Daily Overseas Edition reported. The market was worth about 8.5 billion yuan. China supplied more than 65 percent of the machines.
In this year's school season, Chinese brands from Yiwu and other cities filled the 2026 Indonesia ASEAN Stationery and Gift Expo in Jakarta. Buyers arrived from Indonesia, Malaysia, Singapore and Thailand. School bags and pencil cases were among the hottest items on their lists. The new printer went with them.
Wang Shanqi, who runs a bag and pencil-case firm in Yiwu, said Thailand placed his largest orders this year. Many school years in Southeast Asia start one or two months earlier than in China. Local distributors came as early as the start of the year, he said, to leave time for shipping.
China is already the world's largest maker and exporter of stationery. Its goods account for about 30 percent of global office-stationery exports. Pens, bags and rulers still move. So does a tool that grew out of a Chinese way of studying: keep the mistakes, and look at them again.
The wrong-answer book used to live in a schoolbag at home. In this year's school season, a version of it sat on a buyer's table in Jakarta.