Correction: Amazon's TenMarks buy
An earlier version of this story incorrectly described TenMarks' history with Amazon. </p><p> <a href="http://news.cnet.com/8301-1023_3-57606966-93/amazon-buys-math-education-company-tenmarks/" >Read the updated story here</a>.</p>
An earlier version of this story incorrectly described TenMarks' history with Amazon.