Purchasing an armload of lottery tickets for the chance to win billions isn’t a very good idea. In 2020, Americans spent $90 billion on the game and the chances of winning a jackpot are about one in 300 million. The problem is that humans have a hard time understanding risk, so they chase the dream of life-changing money. But there’s a simple math lesson that can help anyone make the right decision.

Lottery winners have the option to collect their prize as a lump sum or have lottery organizers invest it in an annuity that will pay them 30 payments over 29 years. The total amount of those payments will be smaller than the advertised jackpot because of taxes and discount rates. But the annuity path protects winners from squandering their wealth and may even help them grow it.

In a rare event when multiple winning tickets match the winning numbers, the jackpot will be divided evenly among them. But the chances of winning any prize in a drawing are still one in 300 million.

Unlike other games, lottery play doesn’t require skill and is determined entirely by chance. But that doesn’t stop millions of people from buying a ticket every week and dreaming about the riches they could buy with a single $2 bet. Those dreams cost taxpayers billions in government receipts they would otherwise have saved for retirement or college tuition. The only way to change this is to teach people how to avoid the illusion of big jackpots.