Gauss’s contributions to mathematics are incredible. If he had been forced to learn mathematics while sitting on his head and wearing a clown suit, he still would have been a mathematical genius.
The common core tries really hard to make math seem “simple.” And it does this by replacing abstract concepts with more concrete concepts, pictures or stories. Math isn’t about that. Math is fundamentally abstract —that’s its power. And yes, math is hard. Math is hard for people who are good at math. Humans aren’t computers, but there are many things that we can learn best by memorization. I don’t need to know why five times three is fifteen, I just need to know that it is. If, someday I want to understand why, then I can study group theory, ring theory, and number theory. But most people do not choose to pursue mathematics to that level. Even those of us who do still rely on our memorization of formulas in our daily lives. I can’t imagine being able to go through my day without being able to rely on the memorization of facts, algorithms, and formulas pounded into my head as a child.