Take the following C code (K&R pg. 77) :
push(pop() - pop()); /* WRONG */
The book says that since - and /
From Fabulous Adventures In Coding: Precedence vs Associativity vs Order:
Another way to look at it is that the rule in C# is not "do the parentheses first", but rather to parenthesize everything then recursively apply the rule "evaluate the left side, then evaluate the right side, then perform the operation".