How many numbers have the product code of 2.6?
CREATE TABLE "table1_20124413_2" (
  "num" text,
  "original_title" text,
  "directed_by" text,
  "written_by" text,
  "original_airdate" text,
  "prod_code" text
);
SELECT "num" FROM "table1_20124413_2" WHERE "prod_code"='2.6';