Mathematical representations can be used for two main purposes:
to help students develop an understanding of mathematical concepts and procedures, OR
to help students solve problems.
The materials make thoughtful use of representations in both ways.
Curriculum representations and the grade levels at which they are used are determined by their usefulness for particular mathematical learning goals. Across lessons and units, students are systematically introduced to representations and encouraged to use representations that make sense to them. As their learning progresses, students are given opportunities to make connections between different representations and the concepts and procedures they represent. Over time, they will see and understand more efficient methods of representing and solving problems, which support the development of procedural fluency.
In general, more concrete representations are introduced before those that are more abstract. There are a couple of key progressions of representations that occur across grade bands in different domains.
These progressions, as well as the descriptions at the link below, can be helpful in providing support for students who have unfinished learning and would benefit from more concrete representations to make sense of mathematical concepts.
Scroll to "Representations in the Curriculum"
Begins in Grade 3
Grades 3 to 4
Grades 3 to 4
Grades 4 to 5
Grades 4 to 5
Grade 5
Grade 5