Topic A begins with a
lesson in which students generate categorical data, organize it, and then represent it in a variety of forms.
Drawing on Grade 2 knowledge, students might initially use tally marks, tables, or graphs with one-to-one
correspondence. By the end of the lesson, they show data in tape diagrams where units are equal groups
with a value greater than 1. In the next two lessons, students rotate the tape diagrams vertically so that the
tapes become the units or bars of scaled graphs