Since the Core Knowledge series was introduced, hundreds of thousands of children have benefited from these books' effective and user-friendly knowledge based curriculum. Researchers at the Core Knowledge Foundation constantly refine and update the curriculum based on feedback they receive from parents and teachers across the country. This new, revised edition of What Your First Grader Needs to Know reflects the fruit of that research and features a complete redesign with 32 pages of color. Edited by E.D. Hirsch, Jr. and John Holdren.