CREATE TABLE table_2900 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "U.S. viewers  ( millions ) " TEXT)

What's the series number of the episode directed by Skipp Sudduth?
SELECT "No. in series" FROM table_2900 WHERE "Directed by" = 'Skipp Sudduth'
SELECT "No. in series" FROM "table_2900" WHERE "Directed by" = 'Skipp Sudduth'