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    • ▾Kindergarten
      • ▸Counting and place value
        • •Counting from pictures, oral response
        • •Counting objects by property
        • •Counting to 100 by ones
        • •Counting to 100 by tens
        • •Counting on by ones or tens
        • •Understanding zero
        • •Write numbers
        • •Counting objects, line or rectangular array
        • •Counting objects, scattered and circular arrangements
        • •Compare by matching or counting
        • •Compare written numerals
        • •Counting by category
        • •Count, represent and write teen numbers
      • ▾Addition and subtraction
        • •Add and subtract within 5
        • •Composing and decomposing within 10
        • •Addition, missing number word problems
        • •Addition and subtraction, concrete and visual
        • •Add and subtract within 10
      • ▸Measurement and geometry
        • •Compare measurements without tools
        • •Measurement tools
        • •Naming shapes in the real-world
        • •Naming shapes regardless of orientation or size
        • •Relative positions
        • •Identify shapes and solids
        • •Compare attributes of shapes and solids
        • •Build solids
        • •Compose 2D shapes
        • •Simple repeating patterns
        • •Growing patterns
     › Kindergarten › Addition and subtraction

    Composing and decomposing within 10

    Use Unifix cubes, five frames, ten frames, and number bonds, to explore ways to make numbers 1-10. For example, 4 can be shown as 1 red cube and 3 green cubes. For at least one of the small numbers, arrange in an array, such that students can see 0 + 4 = 1 + 3 = 2 + 2 = 3 + 1 = 4 + 0. I think this is good for students to see enumeration, that is, all the ways something can be done. This is a good brush for later when they study combinatorics in high-school.

    Watch the first part of this video:

    Composing Numbers & Decomposing Numbers! by Scratch Garden

    Making small numbers in different ways by Khan Academy

    Khan Academy doesn't have a lesson on this topic.

    K.OA.A.3: Decompose numbers less than or equal to 10 into pairs in more than one way, e.g., by using objects or drawings, and record each decomposition by a drawing or equation (e.g., 5 = 2 + 3 and 5 = 4 + 1).