Development of the scope and sequence for Holt Science called for careful to the selection of concepts and skills for each grade level. As children develop intellectually, it is important they be taught concepts and skills generally appropriate to their age group. The science program should continuously reinforce skills that are taught and provide opportunities for students to apply these newly acquired skills to many different areas of science. The goal of the program is to expose students to all the major science disciplines and provide them with the fundamental science skills.