» How important is math to being a winning poker player?

Knowing the math of poker can be key.  Knowing the square root of an isosceles triangle not so key.

 Poker math is a tool. The math of poker allows a player to understand when a specific move might be profitable.  Or not profitable. Most poker math, such as odds, can be memorized.  Clearly, if you know the odds of flopping a flush are 118-1, you are less likely to play Q6suited.
   

Actually, not knowing the math is the key to becoming a losing player.