i usually add up the 3 numbers, like 894 = 17+4 = 21 = 3

so just like with tarot as you know about tarot - the 3 has a meaning, it's a building block, 2 parts creating a whole, the birth of wisdom, the holy trinity, many meanings for 3.

You could search tarot number meanings. Or this one on numerology is interesting:
Numerology Chart & Meanings

just some ideas - interesting topic.