The numbers are a cycle. When studying the Tarot or doing readings, keep in mind that if a number comes up the numbers preceding and following the card have significance. If I were to pull the 3 of Swords for a Querent I could determine that their future will be potential to collapse and deconstruction. You can then assume that the current or past state of the Querent may be equivalent to the 2 of Swords, which would mean the cause of the potential collapse was caused by unstable tension. Of course, if there was a card in the ‘past’ or ‘present’ position in a spread it would take priority. Even so, it may be a good idea to keep this concept in the back of your head for possible use.