国庆节期间,我和好朋友管畅一起摆摊卖东西,这是我第一次摆摊。摆摊时,我和管畅一时半会儿忙不过来,只记了卖多少个和卖多少钱。收拾摊要回家时,管畅提醒看看记账本,但我俩一看,呀!没记挣多少钱,“惨了!”管畅伤心地说,“咱今儿挣钱白费了。”“别灰心!数学应该能帮咱解决问题。”我拍拍管畅的肩膀,自信地说。我们问了坐在一旁的爸爸,爸爸担心我们不明白,举了一个例子。假如一个本进货价是五角钱一个,你们卖了一元,挣了多少呢?“五角钱”我说道。爸爸接着说:“这个笔如果进价三元,卖了五 During the National Day, I and my friend Guan Chang set up a stall to sell things, this is my first stall. When setting up a stall, I and Guan Chang are busy for a short while, only remember how many sell and how much to sell. To clean up the booth to go home, Guan Chang reminded to look at the bookkeeping, but we look at it, ah! Did not remember how much money, ”miserable! “ Tube Cheung sad to say, It’s a waste of money. ”“ Do not be discouraged! Mathematics should help us solve the problem. ”“ I patted Guan Liang’s shoulder and said confidently. We asked Dad sitting aside, dad worrying that we do not understand, cite an example. If one of the purchase price is a pentagon, you sold a dollar, earned how much? ”“ Five cents ”I said. Dad went on to say: "This pen if the purchase price ternary, sold five