百分變化 | Percentage Change

影片內容：

00:05 – 百分變化的概念 | concepts of percentage change
02:13 – 盈虧和折扣 | profit / loss and sales discounts
05:17 – 「部分」的百分變化 | percentage change in parts
07:53 – 連續百分變化 | successive percentage change
10:25 – 恆率變化 | change in constant rate