I fully agree that (high) school math is mostly calculus and very different from university/research math. I would recommend parent to start exploring what math actually is, which fields there are and where they come from, what some famous open problems are and what beauty means to mathematicians.
Good popular maths books are e.g. The Music of the Primes by Marcus du Sautoy [1] or Fermat's Last Theorem by Simon Singh [2].
It's also important to note that there are no shortcuts - it takes at least 1-2 years of studying maths to start to understand the why.
I fully agree that (high) school math is mostly calculus and very different from university/research math. I would recommend parent to start exploring what math actually is, which fields there are and where they come from, what some famous open problems are and what beauty means to mathematicians.
Good popular maths books are e.g. The Music of the Primes by Marcus du Sautoy [1] or Fermat's Last Theorem by Simon Singh [2].
It's also important to note that there are no shortcuts - it takes at least 1-2 years of studying maths to start to understand the why.
[1] https://en.wikipedia.org/wiki/The_Music_of_the_Primes
[2] https://en.wikipedia.org/wiki/Fermat%27s_Last_Theorem_(book)