Unit 9 Overview:

In this unit, children will revisit geometry concepts they learned earlier in the year. They will identify and sort both two-dimensional and three-dimensional shapes based on their defining attributes. They will use 2D and 3D shapes to compose new shapes and will examine these shapes to identify their shape parts. The children will partition shapes in equal shares using the words halves, fourths and quarters.

• Students will distinguish between defining attributes (e.g., triangles are closed and three-sided) versus non-defining attributes (e.g. color, orientation, overall size); build and draw shapes to possess defining attributes. (1.G.A.1)
• Students will compose two-dimensional shapes (rectangles, square, trapezoids, triangles, half-circles, and quarter circles) or three-dimensional shapes (cubes, right rectangular prisms, right circular cones, and right circular cylinders) to create a composite shape, and compose new shapes from the composite shapes. (1.G.A.2)
• Students will partition circles and rectangles into two and four equal shapes, describe the shares using the words halves, fourths, and quarters, and use the phrases half of, fourth of, and quarter of. Describe the whole as two of, or four of the shares. Understand for these examples that decomposing into more equal shares creates smaller shapes. (1.G.A.3)