In this lesson, Becca Sherman introduces the “Singapore Bar Model” to students who have never seen it in before.
She uses the context of solving division story problems to introduce the model.
The number talk connects the basic components of the Bar Model with students’ original thinking, thus front-loading students with several applications of the Bar Model as a representation of equal parts. The exploration of story problems incorporates original pictorial representations in order to introduce the Bar Model as simply another representation to understand division.
After watching this lesson, teachers should better understand the ways that students are challenged and engaged by interpreting language. Some challenges include:
- Students with fragile understanding of how multiplication and division are connected struggle with language such as “three times.”
- The intermediary step of drawing a “math picture” or model of the problem challenges many students who have limited exposure to models. These students tend toward calculations without models or very detailed pictures, which do not necessarily aid in understanding the mathematics of the story.
- For some students, multi-digit multiplication becomes a distraction from the problem (which does not require multi-digit multiplication).
Though this lesson takes place in a 4th-grade classroom, it was crafted in response to a different classroom of 5th-grade students who were struggling with story problems requiring division. In a neighboring classroom, students were taught a parallel lesson with the same content, but with a “direct teaching” instructional style. The intent was to compare student responses from the two lessons.