<p>Shortly after his world history students began a pilot program testing a digital textbook for the iPad, Ken Halla noticed something different: His students were actually reading their textbooks.</p><p>"How crazy is that?" said Halla, a ninth-grade teacher at Hayfield Secondary School in Alexandria, Virginia. "To me, it's really great when the kids get excited to read."Ken Halla works with World History students using iBooks textbooks at Hayfield Secondary School in Alexandria, Virginia.</p><p>Of course, Halla admits, the $15 iBook textbook his students usedWorld History: Patterns of Interaction from Houghton Mifflin Harcourtwent beyond the usual text-on-paper approach found in textbooks. Students were taking interactive quizzes, watching videos; even touring ancient European caves to look at prehistoric drawings.</p><p>"To call it a book anymore," Halla said, "is a false pretense."World History from Houghton Mifflin Harcourt lets students explore topics through reading as well as videos and interactive quizzes.</p><p><a href="http://www.macworld.com/article/2039650/grading-apples-digital-textbook-technology.html">Keep reading...</a></p>