Around the country, schools are increasingly dumping heavy, expensive printed textbooks and putting the material online.
It can be pricey, especially for a public school district, but a Roman Catholic boys' school in the New York City suburbs has gone all-in.
Except for the books on religion, all the texts the school uses, from freshman biology to advanced computer programming, are part of a "digital bookshelf" they carry in their laptops and tablets.
Digital books can go beyond their paper counterparts. A history book includes newsreel footage of Woodrow Wilson. A science book shows scientific processes in motion. An English book detects a weakness in grammar and offers help.
Educators say it's an easy transition because students today are "digital natives" accustomed to learning online and on the computer.
Explore further: What if our children are the screen-obsessed couch potatoes of the future?