The first paper money appeared in China.
最早的纸币，是在中国出现的。
It came out during the Northern Song.
它出现在北宋那会儿。
People used heavy iron coins back then.
那时候大家用的，是沉甸甸的铁钱。
Carrying a lot of iron coins was tiring.
扛着一大堆铁钱出门，可太累了。
Merchants left coins at a money shop.
商人们就把钱存进钱庄里。
They got a paper note back instead.
换回一张小小的纸票子。
That note was the first paper money, called Jiaozi.
这张纸票，就是最早的纸币交子。
