CREATE TABLE table_3910 ("Series #" FLOAT, "Season #" TEXT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "U.S. viewers  ( millions ) " TEXT)

What is the episode number of 'Dance Cards and Greeting Cards'?
SELECT MAX("Series #") FROM table_3910 WHERE "Title" = 'Dance Cards and Greeting Cards'
SELECT MAX("Series #") FROM "table_3910" WHERE "Title" = 'Dance Cards and Greeting Cards'