CREATE TABLE table_4169 ("Series #" FLOAT, "Production Code" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "United States Original Airdate" TEXT, "Canada Original Airdate" TEXT)

What number episode in the series had and original United States air date of December 24, 2010?
SELECT MAX("Series #") FROM table_4169 WHERE "United States Original Airdate" = 'December 24, 2010'
SELECT MAX("Series #") FROM "table_4169" WHERE "United States Original Airdate" = 'December 24, 2010'