Illuminations: Supreme Court Handshake

During this lesson, students will explore the handshake problem, a classic problem in mathematics that asks, “How many handshakes occur when n people shake hands with each other?”

Groups work to determine how many handshakes take place among the nine Supreme Court justices, and then generalize to the number of handshakes in any size group. Students explore the problem using a verbal description, a table, a graph, a picture, and an algebraic formula.


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Algebra & Pre-Algebra
Middle School, Educator

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Illuminations (National Council of Teachers of Mathematics)

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