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# 8 Math Lessons You’ll Actually End Up Using in Real Life

## You're probably using math way more than you think.

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## Math matters

While studying for a difficult math test, or enrolling in a required math class, you’ve probably thought to yourself, “When will I ever need this in real life?” (Go ahead, admit it.) But while you might not be using complicated calculus on a daily basis, you can’t deny that plenty of math concepts drive our daily lives. From the food we eat to the houses we live in, many aspects of life would be a whole lot more confusing without good old mathematics. Here are eight math concepts that make day-to-day life a lot easier. (And even if you reach for a calculator to do these things, there’s no denying that you still know what needs to be done—and you can thank math for that.) Think you’re a math expert? Put your skills to the test and try to pass this math test for fifth graders.

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## Telling time

We do it every day. It probably seems like second nature. But it’s all math! Your grandma is having Thanksgiving dinner at 5 p.m. You live an hour and forty minutes away. What time do you need to leave? Or, an even more common scenario: you start work at 9 in the morning, it takes you 25 minutes to get there, and it takes you 40 minutes to get ready in the morning. What time do you need to go to bed the night before to get your full eight hours of sleep?

And don’t even get us started on time zones. As a California native, what time do you call your best friend who’s studying abroad in Italy so that you won’t wake her up in the middle of the night?

Telling time relies quite a bit on addition and subtraction, but there’s more to it than that. You use fractions whenever you think of an hour as a “whole” and minutes as its “parts,” which certainly comes into play a lot while telling time. Here are 11 of the most famous riddles in history.

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## Multiplying and dividing fractions

You’re having a big dinner party. You want to make your favorite pasta dish. But your recipe only makes four servings, and you’ve got a lot more than four people coming over. You’re going to have to double the recipe—and for that, you need to know how to double a a quarter of a teaspoon, a third of a cup, and two-and-a-half tablespoons. Better keep those fractions fresh in your mind! And, of course, the reverse is true if you’re making less of a dish than the recipe calls for. If you only have enough garlic to make half of your favorite pasta dish, get ready to divide those fractions. Of course, another great reason to learn math is so that you can get these 36 hilarious math jokes.

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## Measurements

If you’re doing any sort of architectural project, math might be just as important a tool as a hammer and nails. If you want to do any home improvement projects that you can DIY, you’ll need to know how to measure and calculate everything from distance to surface area. Want to cover your wall with wallpaper or paint? You’d better know how to calculate surface area, so that you know how much to buy. Want to renovate your bathroom? If you don’t use math, you could end up with a bathroom door that bangs into your toilet when you try to close it. These are the 12 math riddles only the smartest people can figure out.

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## Algebra

Those frustrating “find x” problems may not have seemed useful in school, but they can help you shop smarter. Imagine that you have 40 dollars to spend at the grocery store. You know you need to buy three boxes of cereal, four loaves of bread, and three jars of tomato sauce. Also, you really want to buy some candy. If cereal boxes are each \$4, loaves of bread are \$2, and jars of tomato sauce are \$5, how many candy bars can you buy? These 15 word puzzles will leave you stumped.

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## Dividing and multiplying decimals

If you’ve ever figured out how much to tip your waiter, or your taxi driver, you’ve made use of those pesky decimals that you started learning about in third grade. Moving the decimal point over to find 10 percent of your bill, and then doubling that number, might be just as quick as using a calculator once you get the hang of it. By the way, this is how much you should be tipping in any situation.

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## Percentages

You’re shopping at Bed Bath and Beyond and you see an amazing, must-have item that costs \$21.99. Since you’re a savvy shopper, you have a 20 percent off coupon and a \$5 off coupon. Which coupon should you present at the register? Or your favorite new book has hit stores, and you want to buy it. It’s \$19.99 at Barnes & Noble and \$16.49 at Target, but you just got a 30 percent off coupon for Barnes & Noble in the mail. Which store has the better deal? Both of these scenarios require you to find percentages—of decimals, no less. But it’s worth it—math saves you lots and lots of money. Up for a math challenge? Try solving these math puzzles as a delightful challenge.

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## Statistics

Should you invest in the stock market? What risk are you at for certain diseases? What are America’s safest and most dangerous cities to visit? To answer all of those questions, you’ll need to understand statistics. As much as you may have griped about graphs in school, you’ll be happy you can read them when you’re looking up news and statistics of any kind. Check out these 12 funny statistics about average Americans.

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## Physics

Maybe you don’t use physics on a daily basis. But if you’ve ever been to an amusement park and taken a ride on a roller coaster, you should be very thankful that those ride designers paid attention in physics class. Designing, and then building, those loops, drops, and hills requires a precise knowledge of concepts like velocity, acceleration, and momentum. Who says math isn’t fun?! Next, check out the 25 hardest riddles of all time.

[Sources: mathnasium.com, thinkthroughmath.com, mathigon.org]

Meghan Jones is a word nerd who has been writing for RD.com since 2017. You can find her byline on pieces about grammar, fun facts, the meanings of various head-scratching words and phrases, and more. Meghan graduated from Marist College with a Bachelor of Arts in English in 2017; her creative nonfiction piece “Anticipation” was published in the Spring 2017 issue of Angles literary magazine.