Check out this compeling video from Andrew Stadel. What do you notice? What do you wonder? How can this be used to teach students about adding fractions?
I conducted a lesson study about fractions with some 5th grade teachers. We used Andrew’s elegantly simple lesson called Black Box 2 to get students talking about adding fractions with unlike denominators. This task is ideal for introducing the intellectual need for finding a common denominator before adding fractions procedurally. Student discourse is rich and meaningful and lively. Give it a read. You won’t be disappointed.