California Early Math Project 2020

Geometry

In first grade, students reasoned about attributes of geometric shapes. A critical area of instruction in second grade is for students to describe and analyze shapes by examining their sides and angles. This work develops a foundation for understanding area, volume, congruence, similarity, and symmetry in later grades.

 

Students identify, describe, and draw triangles, quadrilaterals (squares, rectangles and parallelograms, and trapezoids), pentagons, hexagons, and cubes. Pentagons, triangles, and hexa­gons should appear as both regular (having equal sides and equal angles) and irregular. Second-grade students recognize all four-sided shapes as quadrilaterals. They use the vocabulary word angle in place of corner, but they do not need to name angle types (e.g., right, acute, obtuse). Shapes should be pre­sented in a variety of orientations and configurations.

 

Partitioning figures is the basis for the study of fractions in later grades. The concept of equal shares is the focus. For example: