First off, don't call it an "XML script" - the word 'script' implies it's directly executable or interpretable, like a python script file, or a Windows batch file. XML isn't: it's a complex hierarchical data transfer format which has just 5 special characters:
<, &, >, ", and '
None of those are a "division symbol", so no such symbol is significant to XML.
Where it may be significant is in the app that processes your XML data - it may do what it likes with it including working out that
99 / 3
should be replaced with
33
for example, but that isn't an XML operation, it's an app operation.
So look to the processing app and what it expects: data read from XML isn't processed it's just passed to the app to do with as it pleases!