数学的真知在于完美，追求问题的最优解如最大、最小、最多、最少等是现实生活中最常见的，也是数学竞赛中典型的赛题。本讲拟从两大方面介绍一些这类问题。一、数中的最值问题例１用１，２，３，４，５，６，７七个数字组成三个两位数，一个一位数，并且使这四个数之和等... Mathematical knowledge is perfect, the pursuit of the optimal solution of the problem such as maximum, minimum, maximum, minimum is the most common in real life, but also a typical mathematical contest contest. This speech intends to introduce some of these issues from two major aspects. First, the number of the most value problem Example 1 with 1,2,3,4,5,6,7 seven numbers composed of three double digits, a single digit, and the sum of these four numbers. .