Math CentralQuandaries & Queries


Question from Carol, a teacher:

What is the correct term for when a child writes 61 instead of 16, or 83 for 38--when they switch the place values of a number?


The error is called a TRANSPOSITION ERROR. But such errors are not confined to children -- we all make them. That is why identification numbers like those found on your driver's license and passport, on barcodes, and many other places, contain a check digit which detects a transposition error made when copying the number. You can learn more about these notions from Wikipedia -- look up "transposition error" and "check digit."


About Math Central


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.
Quandaries & Queries page Home page University of Regina PIMS