Description

There appears to be a typo in the _strip_string function of the math_equivalence.py file, where an unnecessary escape character is used with the percent sign. The code uses string.replace("\%", "") when it seems to me that string.replace("%", "") was intended. I'm not 100% certain whether this behavior is unintentional but currently is_equiv("50%", "50") == False. The current code also throws a warning for python 3.11.

Suggestion

string = string.replace("\%", "")
->
string = string.replace("%", "")