DASH materials are sequential and accommodate variations in student developmental stages and concept, skill, and cognitive style differences through hands-on, activity-based materials rooted in real-world, concrete, practical experiences; graphic, oral, writing, lyrical, and kinesthetic - as well as reading - modes of communication; cooperative group projects permitting peer sharing, teaching, and differential contribution; exploration of application before explanatory investigations; extensional experiences through activity centers and home inquiry; graphic and manipulative - as well as arithmetic - approaches to quantitative requirements.