as somebody that used to love math before university burned me out, this is...really nice
i always loved the understanding why part of math, i loved to learn why a formula worked a specific way, but then university started just shoving formulas without explaining where they come from or what are they used for and not even the teachers could answer that question
having this child get to those formulas her own way is really cool, she actually understand the rules of math and i hope her math system is actually consistent and explained at some point, i haven't tried to understand it because while i have my theory that the circle must have a meaning depending of the angle and wich part is filled, i don't have a way to confirm any theory i make of their meaning until the manga itself reveals it
they haven't done anything wrong mathematically yet so i would hope the writer is a math fan and thats why they made this story