Really cute, glad I found this.
Altho is math flexible? I thought equations are supposed to be the most structured thing? I think if it had something to do with science and finding the equation to certain amounts/increments, that would have made more sense since that requires flexibility in remembering formulas, but literally if an equation asks you what 1+1 is, I don't see what kind of flexibility you need in order to understand an equation.
Other than that, this manga is cute.