星期五的下午,我和妈妈一起来到学校对面的星火文具店买学习用品。来到星火文具店,我选了2包大书皮,2包小书皮,一个铅笔袋,一支蓝色的钢笔,还有一瓶黑墨水。妈妈说,共需要多少钱,你会算嘛?我很自信地回答道,我会算。2包大书皮,1包6元,2包就是12元;1包小书皮5元,2个5元就是10元;一个铅笔袋18元;一支钢笔9元; Friday afternoon, my mother and I went to the school across the Spark stationery shop to buy school supplies. Coming to Spark Stationery store, I chose 2 large book covers, 2 small book covers, 1 pencil pocket, 1 blue pen, and 1 bottle of black ink. Mom said, how much is a total cost, you will count? I replied confidently, I will count. 2 large package of books, a package of 6 yuan, 2 packages is 12 yuan; 1 small book cover 5 yuan, 2 5 yuan is 10 yuan; a pencil bag 18 yuan; a pen 9 yuan;