Uh, no it is not.   I am guessing that I am at least as old as you are, if not older, and it was never taught that way when I was in school.

"For example, in 2 + 3 × 10, the multiplication must be performed first, even though it appears to the right of the addition, and the expression means 2 + 30."

I suggest you find a math teacher, present that equation in the original post, and ask a math teacher what is the correct way to calculate, and what is the correct answer.