Western astrology has long paired each star sign with numbers said to resonate with it. Ruling planets, elements, and numerological symbolism all feed into the pairing — a piece of tradition that's easy to enjoy lightly. Here is what it says for Sagittarius.
In astrological tradition, a sign's ruling planet and element are thought to chime with particular numbers. Layer numerology's symbolism on top, and you get the sign-by-sign lucky numbers that have become a familiar custom.
Star-sign lucky numbers are astrological tradition offered for entertainment — no outcome is guaranteed.