How can we align activities with instructional goals to support student understanding of matter and materials? The Building a Tower Task is intended to elicit preservice teachers’ CKT about descriptions and appropriate uses of materials based on their properties. This task asks preservice teachers to identify the activities that align with the NGSS Performance Expectation that asks elementary students to determine which materials have the properties that are best suited for an intended purpose.The associated resources and activities in this packet, including reading pages, lesson plans, and task, are designed to support teacher educators in in developing preservice teachers’ CKT for teaching about matter and materials by purposefully selecting activities and topics that are organized to build toward the scientific idea described by the Performance Expectation.