Working on math problems together with your kids is a fun way to learn how they think and reason. It has led me to have a deeper emotional connection with my kids as I learn what they struggle with in school. I have slowly learned that some times framing the problem a certain way helps them to grasp what is being taught better than brute-forcing them through exercises and homework.
I don't doubt there are sexism and cultural effects on participation disparities, but ask anyone raising chess-playing children and you'll find notable gender differences in interest level in chess from a young age. Similar is seen on mathematics. There's a classic book from Soviet Russia) where girls' math education was rather highly supported) by an author extremely excited about teaching math to small children. He found that his son lapped it up but he could never get his daughter interested (she would turn his math games into non-math social games), even though she was younger and so had earlier exposure and also benefit of his increased experience practicing teaching on her older brother first. She turned out to be academically successful, but not exceptional in math. Countless parents can tell similar stories.
https://www.amazon.com/Math-Three-Seven-Mathematical-Prescho...
If math pedagogy is your main interest any of the MSRI Math Circle Library books are worthwhile. This includes "Circle in a Box" which is a Math Circle starter kit freely available here http://www.mathcircles.org/GettingStartedForNewOrganizers_Wh...
Lots of great examples/ideas/etc.