Onion Math

Onion Math (洋葱数学) is a K-12 online science tutoring platform founded in late 2013, positioning itself not as content or a tool but as "unmanned K-12 science tutoring" — an automated, teacher-less system that completes the full learning loop including study, practice, testing, diagnosis, AI-powered instant tutoring, and grade prediction . The platform delivers curriculum through 5-8 minute animated videos with intelligent exercises, designed to capture student interest within the first minute in distraction-prone environments .

The company was co-founded by CEO Yang Linfeng (杨临风), who previously worked at BCG and Microsoft and co-founded the rural education NGO Sunshine Bookhouse (阳光书屋) in 2011 before launching Onion Math . Yang and co-founder Zhu Ruochen (朱若辰), a Duke graduate, drew on their公益 background to build a product emphasizing low customer acquisition costs through organic, word-of-mouth growth — reaching 10 million users with minimal marketing spend .

By 2018, Onion Math had raised four rounds totaling nearly 300 million RMB, with investors including FreeS Fund (峰瑞资本), Legend Capital (君联资本), Tencent, and others . FreeS Fund participated in every round from A through D, with the D round closing at 300 million RMB in April 2019 bringing total funding to over 600 million RMB . The platform claimed over 22% user market share in junior high math as of early 2018, with monthly fees around 40 RMB and near-zero marginal costs enabling broad accessibility .