Students verbalized their thinking more frequently during the third task
because they were working with a partner. Although the students may not have realized it
during the class session, the observers noted that students were making comments that
showed they were using fraction addition and subtraction processes. For example,
students made comments such as, “I just need ¼ to win,” and “I can win with a 2/8 to get
to one whole.” These statements demonstrated that students were thinking about the
residual or the “left over part” when they added fractions. Similar findings were reported
in the Rational Number Project, where students who used fraction circles for an extended
period of time were able to compare fractions by using mental images in thinking about
the residual (Cramer, Behr, Post, & Lesh, 1997).