### Standard 9: Geometry and Spatial Sense

In grades K-4, the curriculum should include to- and three-dimensional geometry so that students can:
• Describe, model, draw, and classify shapes

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Benchmarks 9C (The Mathematical World: Shapes)
Shapes such as circles, squares, and triangles can be used to describe many things that can be seen.   Benchmarks 9C (The Mathematical World: Shapes)
Many objects can be described in terms of simple plane figures and solids. Shapes can be compared in terms of concepts such as parallel and perpendicular, congruence, similarity, and symmetry. Symmetry can be found by reflection, turns, or slides.

• Investigate and predict the results of combining, subdividing, and changing shapes
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Benchmarks 2A (The Nature of Mathematics: Patterns and Relationships)
Patterns can be made by putting different shapes together or taking them apart.

Benchmarks 11C (Common Themes: Constancy and Change)
Some features of things may stay the same even when other features change. Some patterns look the same when they are shifted over, or turned, or reflected or seen form different directions.

• Develop spatial sense
Benchmarks 2A (The Nature of Mathematics: Patterns and Relationships)
Things move, or can be made to move, along straight, curved, circular, back-and-forth, and jagged paths.

• Relate geometric ideas to number and measurement ideas
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Benchmarks 9C (The Mathematical World: Shapes)
Areas of irregular shapes can be found by dividing them into squares and triangles.

Benchmarks 9C (The Mathematical World: Shapes)
If 0 and 1 are located on a line, any other number can be depicted as a position on the line.

Benchmarks 9C (The Mathematical World: Shapes)