Amazon is buying TenMarks, a company founded by Rohit Agarwal, for an undisclosed amount. Agarwal’s previous venture, TechTribe, was an Indian focused tech networking site, had been backed by Canaan Partners. TechTribe shut down in 2009, and Agarwal started TenMarks.

TenMarks allows teachers and parents to share mathematics curriculum with K-12 students in the United States, with personalized online math instruction and practice, with hints, video lessons, and real-time results. Terms of the acquisition were not disclosed. Subject to various closing conditions, the acquisition is expected to close in the fourth quarter of 2013.

In a statement, Dave Limp, VP, Amazon Kindle has said that the companies will “develop rich educational content and applications, across multiple platforms.” TenMarks is a freemium service, which gives access to teachers for free, and premium services on offer, and there is an opportunity for Amazon to offer customizable educational content, essentially linked with Kindle and Kindle Fire. It is perhaps not a co-incidence that

TenMarks had raised $3 Million from Catamount Ventures in 2011. Back then, it had claimed that over 15,000 classrooms and 250,000 students across the US had used the service.