分期付款问题 ,课本已做过介绍 ,但处理的方法不易被学生接受 .本文结合例子给出一种比较简单的新方法 .例　顾客购买了一件 5 0 0 0元的商品 .采取分期付款的办法 ,每期付款数相同 .购买后 2个月第一次付款 ,购买后 4个月第 2次付款 ,如此下去 ,到第 12个月付款后全部还清 .如 The installment payment problem has been introduced in textbooks, but the method of processing is not easy for students to accept. This article gives a simple and new method combined with examples. Customers purchase a piece of goods worth 500 yuan. The method is the same for each payment. The first payment is made 2 months after the purchase, the second payment is made 4 months after the purchase, and so on. After the 12th month payment is paid, all will be paid off.