This research-based K-6 program is built to provide instruction on the Common Core Standards, and includes special emphasis on the Mathematical Practices and Learning Progressions at every grade level. Based on the NSF-funded Children's Math Worlds project and over 10 years of research, Math Expressions is proven to be effective in raising student achievement. Hands-on and inquiry driven, Math Expressions Common Core teaches students how to represent solutions and explain their answers. This approach helps develop problem-solving and reasoning skills. The strong emphasis in Math Expressions on representation and discussion opens up the world of mathematics to all learners. Every lesson includes intervention, on-level, and challenge differentiation to support classroom needs.--Publisher.