What is mathematical basis for the percent symbol (%)?

arithmetic notation

Percent means 1 part of 100 or 1/100 and is indicated with %. Per mille means 1 part of 1000 or 1/1000 and is indicated with ‰, so it seems that these symbols indicate the mathematical operations that they perform (i.e., the divisor in per mille is 10X greater. However I can't seem to reconcile how % suggests 1/100 and ‰ suggests 1/1000.

Is this just convention or is there a deeper meaning?

Thank you.


Solution 1:

It's a convention that started sort of as a fluke. In a 14th century Italian manuscript, a sideways letter P is written to stand for 'per 100' or 'per cento'. It then slowly evolved. A more in depth bit can be found under the percent sign history here, and on the wiki page.

In addition to percent 0/0, and permil 0/00, there is also permyriad 0/000 for 1/10000.

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