Parents and students know full well college textbooks are expensive. Chegg Inc., an online textbook rental company, has another option for them, at least for some courses.

Chegg is working with OpenStax College and the 20 Million Minds Foundation to offer digital textbooks for less than $5 each, which students can use with Chegg’s eTextbook Reader software. Any device with an Internet connection can use the Chegg eTextbook Reader.

Digital OpenStax textbooks for Introductory Sociology, College Physics and Statistics are available now, with Introductory Biology and Physiology textbooks coming this spring, Chegg says. Students using one of the textbooks also get access to Chegg’s Homework Help question and answer forum.

Chegg, No. 274 in the Internet Retailer Top 500 Guide, says colleges are adopting digital textbooks as a way to counter rising higher education costs at the same time as the number of online schools is increasing.

“We’ve turned a corner in higher education because the system has acknowledged that the Internet is the clearest path to expanding affordable educational opportunities,” says Dan Rosensweig, Chegg president and CEO.

Both OpenStax College and 20 Million Minds Foundation are not-for-profit organizations devoted to reducing textbook costs.