Former premier Wen Jiabao mingled with pupils at a middle school in Chengde in Hebei province, delivered a talk on science and even joined in a round of rope skipping.
The visit is the latest in a string of public appearances by retired former top officials, who traditionally shun the limelight after stepping down.
Wen stopped by the Liudaohe Middle School on Wednesday, honouring a promise he made on a previous visit in April to return and teach a class.
Wen, 71, appeared to be in good physical shape - at one point he skipped rope with pupils aged between 12 and 15.
The visit came ahead of President Xi Jinping's appearance at a school that caters to ethnic minority pupils in Beijing.
Wen, who studied engineering and geology at the China University of Geosciences, spent the past month preparing his talk, school principal Jia Limin told the South China Morning Post.
"He shared stories about geologists with the students" and explained the importance of studying geography, Jia said.
Clad in his trademark uniform of running shoes and white short-sleeved shirt, Wen "was in good spirits and looked healthy", Jia said.
Pictures from the school showed Wen standing in a large classroom, with maps of China and the world on the blackboard.
After his talk, Wen sat in on a Chinese-language class, lined up at the cafeteria with the pupils and joined them for a spot of tai chi.
He was not accompanied by any other senior-level officials, Jia said.
Wen is widely perceived on the mainland as an everyman figure who is passionate about education. A compilation of his speeches and letters, Wen Jiabao on Education, was published in October.
Wen has appeared in the public eye more than his former peers on the Communist Party's all-powerful Politburo Standing Committee.
His previous public appearance was in October, when he attended an event in honour of Xi's father, the reformist figure Xi Zhongxun.
Meanwhile, the president yesterday visited the Beijing Haidian National Primary School, for an oath-taking ceremony for new members of the Young Pioneers of China, mainland media reported.
Television footage showed Xi accompanied by Vice-President Li Yuanchao and Vice-Premier Liu Yandong.
The school offers classes in ethnic minority languages and culture, and more than 10 per cent of its pupils come from a minority background.
Many retired leaders have appeared in public over the past two months, including former president Jiang Zemin, his successor Hu Jintao, and former vice-president Zeng Qinghong.