Originally Posted by Linguist

These particular rules haven't changed in a very long time.

"The basic rule (that multiplication has precedence over addition)
appears to have arisen naturally and without much disagreement as
algebraic notation was being developed in the 1600s and the need for
such conventions arose."

http://mathforum.org/library/drmath/view/52582.html

Originally Posted by baddog

40+ years is hardly newfangled. Have you found anything that states when this rule was conceived?