Charles Darwin would be pleased to know that elementary school children in states that have adopted the "Next Generation Science Standards" (NGSS) are expected to demonstrate their understanding of several core evolutionary concepts, including trait variation and inheritance, fossils and extinct organisms, common ancestry, natural selection, and adaptation. However, he might also wonder how this is accomplished in the demanding 21st-century science curriculum. In files linked to this article, we provide four lesson plans -- with engaging examples, natural selection games, and other interactive activities -- that were designed to cover the NGSS Disciplinary Core Ideas in evolutionary biology for grades 3-5, in two one-hour lessons. The lesson plans were developed by college students under the guidance of evolutionary biologists and in consultation with elementary school teachers, and then field tested in elementary school classrooms, as described in an accompanying research article.