Book excerpt: Compares the number of hours & the percentage of school time spent on core academic subjects during the elementary school week in the U.S. It addresses three central issues. First: the actual number of hours & the percentage of school time the nation's elementary school teachers spend on instruction in the core subject areas of English, reading, & language arts; math; social studies; & science. Second: analyzes how this time varies by characteristics of the local community, school, teacher, classroom, & students. Finally, examines how the amount & percentage of time spent on the core subjects has changed from 1987-88 to 1993-94. Charts & tables.