Curated OER
Even and Odd Numbers Closure Activity
High schoolers explore the concept of closure. In this closure lesson plan, students discuss what it means for something to be closed by using examples of juice and gases. High schoolers add and multiply combinations of even and odd...
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Closure
Dr. Math explains the algebraic concept of closure. Dr. Math gives several examples and explains why the set is closed under the operation or not.