I'm a nuclear engineer by education and stuggled with doing computations using common core methods. I can only imagine how most people who didn't pick a profession that involved advanced math fare when faced with doing long division common core style.

In the US we changed how math is taught about 10 years ago. 1 + 1 is still equal to two, but the children are taught an entire new methodology for calculation. I'm a nuclear engineer and had to re-learn how to do basic maths just to be able to help my children when they struggle with basic arithmetic.

To be honest, the new system (called common core) is incredibly complex and emphasizes proof of work over accuracy and understanding. It is supposed to lead to a better understanding of math. In reality, it's just really complex and difficult to learn.