1. Consider all possible lengths:
* 1-letter words: P, A, S, I, O, N (6 words)
* 2-letter words: PA, AS, IS, ON (4 words)
* 3-letter words: PAS, SON (2 words)
* 4-letter words: PASS (1 word)
2. Add them up: 6 + 4 + 2 + 1 = 13 words
Therefore, you can make 13 words from the word "Passion".