经济学有一个术语：
最典型的例子就是土耳其里拉，目前市场流通的叫新土耳其里拉 Yeni Türk Lirası (YTL)，2005年推出的。美元兑旧土耳其里拉的汇率如下：(source: Wikipedia)
The following are based on yearly averages:
1960s: US$1 = TL 9
1970: US$1 = TL 11.30
1975: US$1 = TL 14.40
1980: US$1 = TL 80
1985: US$1 = TL 500
1990: US$1 = TL 2,500
1995: US$1 = TL 43,000
2000: US$1 = TL 620,000
2001: US$1 = TL 1,250,000
2005: US$1 = TL 1,350,000
The Guinness Book of Records ranked the Turkish lira as the world’s least valuable currency in 1995 and 1996, and again from 1999 to 2004. The lira’s value had fallen so far that one original gold lira coin could be sold for TL 154,400,000 before the 2005 revaluation.
旧里拉的面值在本世纪初已经破了当时的吉尼斯世界纪录了。所以2005年，时任新总理埃尔多安推出了新里拉，就是旧里拉划去六个零，原来的1,000,000里拉变成了1里拉。