Which explains why the Constitution enumerates the president’s formal powers? It makes clear the president’s role as head of the executive branch.
It makes clear the president’s role as head of the office of the president.
It makes clear what the president should do when issuing executive orders.
It makes clear what the president should do when using the mass media.

Currently, as of february 2016, an american traveling in france would be by the exchange rate. the weakness of the euro and the strength of the us dollar means that items in france cost less to an american than they otherwise would. of course, if this trend reverses and the us dollar weakens and the euro strengthens, such as was happening in early 2008, an american traveling in france would have an adverse experience because items would cost relatively more.