No Las Vegas casino would be complete without playing cards. They’re used in blackjack and poker and a variety of other games, including Pai Gow poker, which in Chinese translates as “that card game this blog doesn’t understand because it may involve math.”

So, here’s a question about playing cards: Why are there 52 cards in a deck?

It’s good to be the king.

Come to find out, many believe our modern decks of cards can be tied to astrology. The four suits, for example, are said to represent the four seasons. Not The Jersey Boys, the other four seasons. Please try and stay focused.

The 13 cards of each suit represent 13 months of the lunar new year. A lunar month (“sidereal lunar month” to be precise) has 28 days, so if you multiply 13 months by 28 days, you get 364, which is the number of days in a year in something called the positivist calendar. (It’s actually 364 plus a festival day commemorating the dead, for a total of 365.)

You may have already figured out that our 52-card decks are related to the fact a year has 52 weeks.

For the record, this blog still hates math.

The weight of an average playing card is 0.063 of an ounce. You’ll win a bar bet with that one some day.

Here’s a bonus trivia item about playing cards.

Ever wonder why the ace of spades gets special treatment in terms of its design?

The ace of spades is also known as the “spadille.”

The fancy design got its start under the reign of James I of England. He created a law requiring that an insignia (usually hand-stamped) appear on that card to prove payment of a tax by playing card manufacturers. That special tax existed in the U.K. until 1960, and the practice of putting an ornate spade symbol on the ace of spades stuck around.

Now you know!