Former FNB chief economist Cees Bruggemans writes in his Rex Column published on Moneyweb that

during 2000-2001 the Rand weakened by over 100% (from 6:$ to 13.80:$)…

If the rand weakens by 100%, it means it falls to zero and it would have no exchange value against anything. A currency that falls 100% disappears out of circulation. Clearly the rand is not out of circulation – not yet.

The correct way to calculate how much the rand has fallen in this instance, is to divide $1 by R6, and $1 by R13.8, giving you values of 0.17 and 0.072. This gives you the number of dollars you need to buy one rand.

After the 2000-01 drop in the rand, it took 57% fewer dollars to buy one rand, meaning the rand had fallen 57% against the dollar, not “more than 100%.”

The Zim dollar fell 100%. The rand didn’t.