Open Binance, on the left side you will see "Earn", you will see so many options for generating passive income! And not just Binance, other exchanges have that too! I guess many multicurrency wallets have some staking options now, I am using Atomic wallet for some coins, for example! From casinos where you can earn from dividends to exchanges and wallets, there are so many different ways to make some passive income in crypto!
And numbers are simple to understand, and everything comes down to your bankroll and the level of risk you are willing to take!