What is what does xer mean in math?

In mathematics, "xer" is not a standard or commonly recognized term. It's possible that:

• It is a typographical error or a misspelling of a more familiar term, such as "zero," "xerox" (though the relevance to mathematics would be contextual only), or a term specific to a very niche field.

• It could be a term used within a specific context, classroom, or by an individual researcher that isn't widely adopted.

Without more context, it's impossible to provide a precise definition or explanation. If you encountered "xer" in a mathematical context, please double-check the spelling and provide additional information about where you saw it used. It is possible that the term is being used in an obscure paper and in some cases it is used to name a mathematical term in an academic publication for example.

If you are interested in general mathematical terms and concepts, you might find resources on subjects like algebra, calculus, or geometry useful, depending on the field of mathematics you are concerned with.