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## What are mnemonic devices?

Mnemonic devices are memory aids that help you remember a specific thing. They can be acronyms, sentences, rhymes, or any other device that calls the things you're trying to remember to mind. You may remember learning some of the more common mnemonics, such as "I before E except after C" and "Roy G. Biv" to remember the colours of the rainbow. But we've got plenty more intuitive, accurate mnemonics that you may never have heard of—but will wish you'd always known.

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## Roman numerals

You may not have to use Roman numerals too much in your daily life. But they do pop up sometimes—think about how they're used to identify the number of every Super Bowl!—and when they do, they can make you say, "Huh?" But there's a quick sentence you can use to remember these numbers-that-are-actually-letters. (Or is it letters-that-are-actually-numbers? That's a debate for another day.) Here's the sentence, which requires you to put yourself in the shoes of an enthusiastic percussionist: "I Value Xylophones Like Cows Dig Milk." Each letter represents a change in the numerals as the numbers get higher; for instance, "I" is 1, but then 5 is written as "V," not IIIII. Likewise, you get another new one—"X"—when you reach 10, and so on for 50, 100, 500, and 1,000. Use the sentence to remember the order.

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## Metric system units

If you're American, you probably live and die by feet, inches, and miles—but that doesn't mean knowing the metric system isn't helpful. In fact, you've probably struggled to keep the units of the metric system straight. Well, this mnemonic sentence can help. Just remember the unfortunate (?) fate of the fictional King Henry: "King Henry Died Magnificently Drinking Chocolate Milk." How does this help with the metric system? The first letter of each word is the same as the first letters of the main metric system length units, in descending size order: kilometer, hectometer, decameter, meter, decimeter, centimeter, and millimeter.

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## Long division

In school, you may have learned mnemonic devices like "Please Excuse My Dear Aunt Sally" to remember the order of operations for solving equations. But there's a simple trick for long division that might be a little more applicable to your post-elementary school life. It also has to do with order: For each digit in a long division equation, you divide, then multiply, then subtract, then bring down the next digit. So, to remember "Divide, Multiply, Subtract, Bring down," think of this rather gross but true phrase: "Dead Monkeys Smell Bad." Of course, you can always do long division with a calculator. But with this mnemonic device, you can feel proud of your memory retention and your math skills.

Check out these math lessons you'll end up using everyday.

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## Desert vs. dessert

Despite their very divergent meanings, it can be easy to mix up these two words. Luckily, there's a fun mnemonic to help you remember which is which. Think about how "dessert" has two S's, which can stand for an actual dessert, "strawberry shortcake." You can also think about what "dessert" actually is: "sweet stuff." Or, of course, you can always remember the very helpful piece of life advice that "stressed" spelled backward is "desserts" (not "deserts"). Spelling-related mnemonic devices are some of the most common—and the most helpful.

Don't miss these everyday habits that help boost your memory.

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## Months of the year

Sure, the "Thirty days hath September..." rhyme is all well and good. But the fact that there's more than one-month rhyming with "September" can make it more puzzling than it should be—not to mention February's various addenda are just confusing. Instead, try this mnemonic device that doesn't use words at all. Make a fist with both hands and hold them up in front of you. Starting with the leftmost knuckle on your left hand, recite the months, moving over to the right as you say each one. (So "January" is the leftmost knuckle, "February" is the valley between knuckles, "March" is the next knuckle, and so on.) When you reach August, hop from the fourth knuckle on your left hand (July) to the leftmost knuckle on your right hand for August. (Your thumbs don't get to participate here.) Lo and behold, every time you name a 31-day month, you'll be on a knuckle, and when you're at a "dip" between knuckles, you'll be naming a shorter month.

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## The planets

You probably learned some variant on a planet-themed mnemonic in school. In today's eight-planet solar system, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune become "MVery Educated (or Eager) Mother Just Served UNachos." But raise your hand if you're still mourning Pluto and the corresponding "nine pickles" that the "nachos" usurped. Pluto being a planet is one of the things you learned in school that are no longer true.

Impress your friends with these eye-opening facts!

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## The continents

Knowing all of the continents is admittedly probably going to be more useful in your Earthbound life than knowing all of the planets. So there's a mnemonic for that, too. Using the first letters of each continent name—Europe, Asia, Africa, Australia, Antarctica, North America, South America—you can make a couple of different phrases. Try "Eat AAspirin After A Nasty Sandwich," or, more pleasantly, "Eat AApple AA Nice Snack." Of course, now the trick is remembering what each of those many A's stands for, which these mnemonic devices sadly won't help with.

Read on for the most famous riddles in history.

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## The oceans

How many oceans are there on Earth? Well, this question has a more complicated answer than you might think, but the International Hydrographic Organization currently names five. They are: Pacific, Atlantic, Indian, Southern, and the Arctic. And you can remember them with the mnemonic "Pick AIndian Summer Apple." Or the perhaps more practical apple-picking advice: "Pitch All Icky, Slimy Apples."

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## The Great Lakes...in order

You've already got the Great Lakes down, you say, thanks to the fact that you can use the first letter from each lake to spell out the word "HOMES"! And that's helpful, sure—but it just helps you remember what they are, not where they are. If you're a true geography aficionado, use this mnemonic instead to remember them from west to east: Sally Made Henry Eat Oreos. Impress the people in your life by being able to, not just name all of the great lakes, but to identify them. Because if you know their order from west to east (Superior, Michigan, Huron, Erie, Ontario), you'll know where they are.

Unfortunately, this mnemonic can't help you with the geography questions everyone gets wrong.

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## Stalactites vs. stalagmites

It's only two words, but they're so annoyingly similar, and so infrequently used (unless you're a geologist or spelunker), that you probably just throw up your hands when considering which is which. But, thankfully, whoever coined these words had a little sympathy, because one of them has a "C" in it and the other has a "G." And you can remember which is which by thinking about how stalaCtites grow from the Ceiling and stalaGmites grow from the Ground.

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## The Zodiac signs

There's no "cat" Zodiac sign (though Leo, the Lion, kind of seems close enough, doesn't it?), but a phrase about a cat might just help you remember the star signs! Starting with Aries, the signs are: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces. (This is the traditional "order" of the signs.) To remember them, use this sentence: "A Tense Gray Cat Lay Very Low, Sneaking Slowly, Contemplating Pounce."

Here’s the second-grade math problem no one can figure out.

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## Early presidents

Cramming for a U.S. history test? Keep the Founding Fathers straight with this mnemonic device that helps you remember the first 11 presidents, in order: "Will A Jolly Man Make A Just But Harshly Treated President?" The names this mnemonic evokes are: Washington, Adams, Jefferson, Madison, Monroe, Adams (of Quincy Adams), Jackson, (van) Buren, Harrison, Tyler, and Polk. And if you only need to know the early, early, Commanders-in-Chief, try this easier phrase: "Washington And Jefferson Made Many Joke."

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## Mount Rushmore

Be honest: Unless you're a historian, or seriously trying to impress some history-nerd friends, you probably won't need to know the early presidents in order. But what about the guys on America's unofficial President Hall of Fame, Mount Rushmore? You know Washington and Lincoln are obviously on there, but...who else? Just remember the phrase "WJust Like Rushmore." Oh, that's right—it's Washington, Jefferson, Lincoln, and Roosevelt. (Just don't forget that it's Teddy, not Franklin, Roosevelt!)

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## Music notes

If you took music lessons as a kid, you probably learned some classic mnemonic devices to help you learn to read music. And they really do help! The letters of the lines on the treble staff, from bottom to top, are the first letters of "Every Good Boy Deserves Fudge" (or "Does Fine"). The spaces spell "FACE." The bass clef is a little trickier; you can use "Great Big Dogs Fight Animals" or "Good Bikes Don't Fall Apart" to remember the lines and "All Cows Eat Grass" to remember the spaces. These mnemonic devices are also great because, unlike many others, they don't substitute for a full other word but just the letter—that's less remembering for you!

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## Setting the table

Here's a super-simple mnemonic device you never knew you needed. When you're setting a place at the table, the items that go to the left of the plate, "fork" and "napkin," have an even number of letters, like the word "left." Likewise, the things that go to the right of the plate, the knife, spoon, and glass, have an odd number of letters, like the word "right."