Kindergarten Spring Math — Compose/Decompose to 10, Addition & Subtraction within 10, Teen Numbers as Ten-and-Ones, Measurement, and Classification
Math · GM
K
math.gK.s.gm.compose_shapes
Compose simple shapes to form larger shapes (K.G.B.6)
Compose larger shapes from smaller shapes. Specifically: two right triangles compose a square or rectangle; two squares compose a rectangle; six equilateral triangles compose a hexagon; a triangle on top of a square composes a 'house' pentagon; a square + a triangle + a rectangle compose various pictures (house, tree, sailboat). The K-stretch is shape substitution: realize that the same large shape can be composed in multiple ways (a rectangle = 2 squares = 4 right-triangles).
Mastery threshold
90%
Min instances
10
Typical minutes
25
Spaced intervals (days)
1, 3, 7, 14, 30, 60
Prereqs
Successors
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math.g1.s.gm.compose_3d_shapes
(not yet loaded)
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math.g1.s.gm.partition_shapes_into_halves_fourths
(not yet loaded)
Common misconceptions
- Leaves gaps or overlaps when composing — does not see that shapes must tile without gap or overlap.
- Cannot recognize a hexagon when it is composed of six triangles (sees only the small triangles, not the larger shape).
- Rotates the composed shape and reports it as 'a different shape' (rotation-invariance not yet established for composed shapes).
- Tries to fill a hexagon with squares (does not realize squares cannot tile a hexagon).