请根据这道题，制作一个解答思路的教学视频，要求通俗易懂、透彻。---**Title:** 探究性作业：怎样搭配积最大？ (选做) 答案 P157 (Exploratory Homework: How to match for the largest product? (Optional) Answer P157) **Introduction:** 用四个不同的数字组成一个两位数乘两位数的乘法算式，怎样搭配积最大？ 让我们一起来探究一下吧！ (Use four different digits to form a two-digit number multiplied by a two-digit number multiplication expression. How to match for the largest product? Let's explore it together!) **Specific Question:** 用 1, 2, 3, 4 这四张卡片上的数字组成一个两位数乘两位数的乘法算式，怎样搭配积最大？ (Use the digits on these four cards 1, 2, 3, 4 to form a two-digit number multiplied by a two-digit number multiplication expression. How to match for the largest product?) **My Analysis:** 1. 用 1, 2, 3, 4 这四张卡片上的数字可以组成很多两位数乘两位数的乘法算式，如：12×34, 13×24, 23×41, 32×41……怎样搭配才能使它们的积最大呢？ 要使积最大，就需要组成的两个两位数尽可能大，即需要把较大的数字放在十位，较小的数字放在个位。这样，组成的乘法算式有如下两种情况。 (Using the digits on these four cards 1, 2, 3, 4, many two-digit by two-digit multiplication expressions can be formed, such as: 12×34, 13×24, 23×41, 32×41... How should they be matched to make their product the largest? To make the product largest, the two two-digit numbers formed need to be as large as possible, which means putting the larger digits in the tens place and the smaller digits in the units place. Thus, the multiplication expressions formed are of the following two cases.) 算式 1: □□×□□ (Formula 1: □□×□□) 算式 2: □□×□□ (Formula 2: □□×□□) 2. 这两个算式哪个积大呢？列竖式计算，并比较。 (Which of these two expressions has a larger product? Calculate using vertical form, and compare.) 算式 1: (Formula 1:) [Space for vertical calculation] 算式 2: (Formula 2:) [Space for vertical calculation] 所以积最大的算式是 (Therefore, the expression with the largest product is) [Blank line for the answer]