AnonymousIs this a common expression?No, but it is creative—I may use it.
Anonymouswhat does it mean?"Add the prefix 'extra-' to the word 'ordinary' to produce the word 'extraordinary' ." Since 'ordinary' means 'common' and 'extraordinary' means 'uncommon, exceptional, outstanding', the phrase you quote means to make something exceptional out of a rather average thing/idea/product.
Extra means more added to the usual; Excessive; Extravagant.
Ordinary means no special or distinctive features; Normal; Standard.
PUT THE EXTRA;
PUT Meaning Put into; Implement; EXTRA Meaning the Excessive, Extravagant, More than usual.
INTO Meaning add; Ordinary Meaning Normal or Standard.
That quarterback Tom puts the extra into ordinary