In Windows I just highlight the desired Mathematica expression and hit Ctrl+C then move to the Word document,click the mouse at the desired insertion point and hit Ctrl+V. I am not certain but I think that the copy puts the MathML code of the highlighted expression on the clipboard and the Word program automatically interprets the pasted code. I have done a little additional research since asking the question and think I found that I will need to purchase MathType to get equations in Pages. But I still don't know if, even with MathType, I will be able to do the same copy and paste as can be done in Windows.