CREATE TABLE "fourth_round" (
  "tie_no" real,
  "home_team" text,
  "score" text,
  "away_team" text,
  "date" text
);

Question: What was the tie number for the round against visiting opponent Chelsea?
SQL: SELECT SUM("tie_no") FROM "fourth_round" WHERE "away_team"='chelsea';

Question: What was the tie number for the round against visiting opponent Newcastle United?
SQL: SELECT "tie_no" FROM "fourth_round" WHERE "away_team"='newcastle united';