This benchmark receives ample treatment in the material. The skills are given the greatest attention at grades 6 and 7, with appropriately less coverage at grade 8. Across all three levels, students have numerous opportunities to compare and interpret equivalent forms of many different types of numbers. Emphasis is on drill and practice of interpreting and comparing equivalent forms. There is little explicit direction as to when one equivalent form would be more appropriate than another.
Shapes can match exactly or have the same shape in different sizes.
Parts of the benchmark, such as special properties of round shapes and congruence, receive minimal coverage in this material. Triangles receive the most attention in terms of special properties of shapes. There is ample coverage of similarity throughout all three books, but many of the lessons are near repetitions of those found at earlier levels. While there are some lessons and labs that stand out as challenging extensions, the sophistication of the mathematical ideas is low for the grade level at which they are presented. This benchmark is covered primarily in grade 7, with some references in grades 6 and 8.