High Rate of Author's students obtained Scores, from 90 to 99 Percentile, of SAT Math Sections Of the Non-Redesigned Version. Book 1/2 D and Book 2/2 D are designed to provide more than 1,000 question types of categorized SAT math for the students who aspire to achieve a high score on the SAT math sections. The books also provide a lot of the fastest methods of solving the questions by Logical Step Form created by the author. The explorations of this book primarily use the logical steps to let users easily memorize the methods of solving questions. The essence of mathematics is logic. Human thinking naturally accepts the formula of because and therefore. Hence, using mathematically logical steps to solve questions directly is in harmony with the natural function of human brain. Furthermore, it is helpful for memorizing because what you need to remember are the mathematically logical steps, which is refined and easily to be memorized, instead of the mixed explanations of English and math that are difficult to memorize. This book belongs to the series of Mad Math. This series includes SAT Math Database, SAT Math, PSAT Math, SAT Subject Math Level 1 Database, SAT Subject Math Level 1, SAT Subject Math Level 2 Database, and SAT Subject Math Level 2.