This is the second book of the Math Contest Books Series -- This book introduces the new methods to solve balls and boxes distribution problems. The book can be used by students preparing for math competitions such as Mathcounts, and AMC 8/10/12. Each chapter consists of (1) basic skill and knowledge section with examples, (2) exercise problems, and (3) detailed solutions to all problems. First book of Math Contest Books Series. The Mass Points Method: https://www.amazon.com/Mass-Points-Method-Yongcheng-Chen/dp/1523265884Third book of Math Contest Books Series: The Area Method https://www.amazon.com/dp/1540856410 Fourth book of Math Contest Books Series: Problem Solving Using Cauchy's Inequality https://www.amazon.com/dp/1541000285 9th book: Problem Solving Using Auxiliary Lineshttps://www.amazon.com/dp/1975681754 10th book: https://www.amazon.com/Problem-Solving-Using-Vietas-Theorem/dp/1542800056