Seventh- and eighth-graders at Eureka Middle School in Illinois are using electronic textbooks as part of a blended-learning approach to teaching math. Teachers developed digital lessons and assignments, including videos, that allow students to work ahead or get extra help. "[Overall], it's been very positive," eighth-grade math teacher Sandy Tignor said. "Not a single eighth-grade student is doing poorly in math. The lowest grade right now is a low B."