Electronic homework assignments, often times proprietary software curriculums from companies of the like of Pearson Education and McGraw Hill. What does Wikipedia have to say about this? Interesting. So, Pearson is British headquartered, not United States headquartered. And indeed, to confirm your assumption, yes they are the biggest commercial education materials company, bigger than McGraw Hill. Also, nowadays Pearson owns a whole lot of publishing companies that were once separate companies, such as Addison-Wesley, Prentice Hall, etc.
20190102/https://en.wikipedia.org/wiki/Pearson_Education
20190102/https://en.wikipedia.org/wiki/Pearson_plc
20190108/https://www.theguardian.com/education/2012/jul/16/pearson-multinational-influence-education-poliy
So, after this reading, the most interesting thing I learned? Testing is apparently a “huge corporate profit-centre.” So, if you have questions about why testing is so prominent in school days, follow the money trail.