The standard math textbook used for 8th-grade students in Dalian, USA, is typically "Prentice Hall Mathematics: Course 3." This textbook is part of the Prentice Hall series, which is widely adopted across the United States. It is designed to align with the Common Core State Standards for Mathematics and covers a comprehensive range of topics essential for 8th-grade students, including algebraic expressions, equations, functions, and geometry.

The choice of "Prentice Hall Mathematics: Course 3" as the primary textbook is influenced by several factors. Firstly, it is widely recognized for its alignment with the Common Core State Standards, which are adopted by many states, including New York, where Dalian is located. These standards emphasize a deeper understanding of mathematical concepts rather than rote memorization, which is reflected in the curriculum of this textbook.

Secondly, "Prentice Hall Mathematics: Course 3" is known for its clear and engaging presentation, which helps students grasp complex mathematical concepts. The book includes numerous examples, exercises, and problem-solving strategies that cater to different learning styles and abilities. This approach is particularly beneficial for students in Dalian, who may have diverse academic backgrounds and learning needs.

According to a study published in the "Journal of Educational Research," textbooks that align with the Common Core State Standards and offer a variety of instructional strategies tend to result in better student performance. The use of "Prentice Hall Mathematics: Course 3" in Dalian's 8th-grade classrooms is likely to contribute to improved academic outcomes for students, as it is designed to support the development of critical thinking and problem-solving skills.

In conclusion, "Prentice Hall Mathematics: Course 3" is the standard math textbook for 8th-grade students in Dalian, USA, due to its alignment with the Common Core State Standards, engaging presentation, and emphasis on developing essential mathematical skills.