Zimbabwe has the highest inflation rate in the world today, and provides an illustration of the effects of inflation. Consider this news article on CNN on inflation in Zimbabwe, which has picked back up to 7982% in the year ended September.
Relatedly, the Government recently devalued the official exchange rate from 250 Zimbabwe Dollars per USD to 30,000. At the time, commentators mentioned that this was not enough, as the underlying black market rate was closer to 250,000 ZimD per USD. Well now, just one month later, the black market rate has deteriorated to close to 1million ZimD per USD. And that was on October 18.
To understand what 7982% inflation means, that implies a daily compounding inflation rate of 1.21%. (That is, (1+0.0121)^365=(1+79.82)) That's about Hong Kong's annual inflation rate every day, compounding! Put another way, prices double every 57 days ((1+0.0121)^57=2), or about every 2 months. Every 4 months, they quadruple, etc. Based on this back-of-the-envelope calculation, in the unlikely event that you hold some ZimD, sell them fast- the value of the ZimD will be falling approximately proportionally with the inverse of the price level. Since the news story I linked to above was published 11 days ago, the black market rate has likely fallen to about 1.14 million ZimD per USD already!