Those who have the custom to say the Yotzros for Musaf on Shabbos Shekalim finish off each stanza with the following words:
אור פניך עלינו אדון נשא, ושקל אשא בבית נכון ונשא
Hey, wait a second, wasn't it a Machtzis HaShekel - so why does it say V'Shekel?