Michael Kenyon’s students at Green River Community College used to pay nearly $200 for a new pre-calculus textbook. But this quarter, they’ll pay only $20 for a book — or use it online for free.

Kelly Duong and Melanie Khiem both excelled in their math classes at Lowell High School and UMass Lowell. But they can’t say the same for many of their friends and classmates, especially after the ...