The following paragraphs provide an overview of the important concepts and skills students in this grade level will learn. More importantly, teachers are provided a cursory look at how instruction in prior grades has built the foundation for the material in the current grade level. It is imperative that teachers understand that the topics outlined in the paragraphs, as well as the Standards listed within each trimester of the Pacing View, are not exclusive to the trimesters in which they are listed; the Common Core State Standards are not a list of Standards that can be “checked off” once they have been taught. For students to truly master the rigorous concepts and skills of the Common Core State Standards, they will need to be exposed to the Standards in multiple settings and situations, making connections between and among the Standards from different Domains. This will obviously require the revisiting of Standards over the course of the entire year. Finally, to ensure that the Standards are taught to the depth of understanding required in the Common Core State Standards, teachers will need to be keenly aware of how their lessons today can and will be extended and expanded in future lessons that may occur in subsequent trimesters and grade levels.
In second grade, instructional time should be devoted to building fluency with addition and subtraction and extending understanding of the base-ten system. Second grade students build upon their work from first grade in two major ways. They represent and solve situational problems which involve addition and subtraction within 100 rather than within 20, and they represent and solve two-step situational problems. They are continuing to deepen their understanding of addition and subtraction to develop fluency in single-digit additions and the related subtractions using mental counting strategies, and “easier problem” strategies as needed. Fluency involves a mixture of simply knowing some answers, knowing some patterns, and knowing some answers from the use of strategies (OA).
Second grade students also extend their understanding of the base-ten system. This includes comparing amounts and counting by fives, tens, and multiples of hundreds and tens, as well as number relationships involving these units. In second grade, composing and decomposing involves an extra layer of complexity beyond that of first grade. Students must understand that a hundred is a unit composed of 100 ones, but must also understand it is composed of 10 tens. Students in this grade build their understanding of multi-digit numbers (up to 1,000) written in base-ten notations (expanded form), recognizing that the digits in each place represent amounts. They solve problems within 1,000 by applying their understanding of models and properties of addition and subtraction. They develop, discuss, and use efficient, accurate, and generalizable methods to compute sums and differences. They select and accurately apply mental math strategies that are appropriate for the context and the numbers involved (NBT).
In second grade, students continue and extend their work with adding and subtracting to length situations and bar graphs. They recognize the need for standard units of measure and correctly use measurement tools. They recognize that measurement involves an iteration of units and that the smaller the unit, the more iterations they need to cover a given length (MD).
Students expand on the geometry work from first grade by describing and comparing attributes of shapes. They begin to examine sides and angles. Students investigate, describe, and reason about decomposing and composing shapes to make other shapes. Through building, drawing, and analyzing two- and three-dimensional shapes, students develop a foundation for understanding area, volume, congruence, similarity, and symmetry for later grades (G).