If a sequel has a number in the title, that number is usually 2, indicating that the work is the second in the series (followed by 3, etc.). However, sometimes the original work already has a number greater than one in the title. In that case, the sequel title will often add one to that number, instead (with a possible in-story justification).
The original work will often have a better justification for using a number in the title than the sequel does. So, the title of the film The Whole Nine Yards refers to a common English expression, but The Whole Ten Yards doesn't.
- 21 Jump Street and 22 Jump Street
- Ocean's Eleven, Ocean's Twelve, and Ocean's Thirteen
- The Three Musketeers (1973) and The Four Musketeers
- The Whole Nine Yards and The Whole Ten Yards
- 101 Dalmatians (the 1996 live action version) and 102 Dalmatians (its 2000 sequel).
- Three-Headed Shark Attack is the sequel to Two-Headed Shark Attack, not the third in a series. Confusingly, Five-Headed Shark Attack is the next one in the series, with Six-Headed Shark Attack after that, skipping over a hypothetical Four-Headed Shark Attack.
- Master of the Five Magics, Secret of the Sixth Magic, and Riddle of the Seven Realms by Lyndon Hardy.
- Soul-Junk uses and inverts this. Their first album was named 1950. Albums that followed counted up (1951, 1952...), while EP's counted down (1949, then 1948...).