Teachable Moments in Math

One morning during the daily calendar routine, Ms. Baxter asks her 1st graders to think of a variety of ways to express the number of the day—12. Her exuberant students come alive with ideas to share. One child suggests 6 + 6, another 10 + 2. Others suggest 2 + 2 + 2 + 2 + 2 + 2 and 5 + 5 + 2. Finally, another one proposes 11 + 1. Ms. Baxter writes each expression on the whiteboard.

The next day, she writes 12 = ___ + ___ on the board and asks the students to recreate their thinking from the day before. Expecting a flurry of hands, Ms. Baxter is surprised when her students' faces show puzzlement. "You wrote it wrong," one child says. "It's backward," says another. More comments follow: "Put the 12 on the other side." "You can't write the answer first!"