Upworthy's book GOOD PEOPLE comes out on September 3, 2024 — take a look!

Shop
 Explore 

math

Education

Math professor shows how adding and subtracting left to right is actually easier and faster

Mind. Blown.

Howie Hua/TikTok

Howie Hua shares helpful math tips and tricks on social media.

Math is weird.

On the one hand, it's consistent—the solutions to basic math problems are the same in every country in the world. On the other hand, there are multiple strategies to get to those solutions, and it seems like people are still coming up with new ones (much to the chagrin of parents whose kids need help with homework using methods they've never learned).

Math professor Howie Hua shares math strategies that make math easier on social media, and his videos are fascinating. Hua, who teaches math to future elementary school teachers at Fresno State, demonstrates all kinds of mental math tricks that feel like magic when you try them.

For instance, Hua has two videos showing how easy and quick it is to add multidigit numbers left to right instead of right to left, and it's genuinely mind-blowing.

Check out how he explains why adding left to right is "underrated."

\u201cNew TikTok video: Adding left to right is underrated\u201d
— Howie Hua (@Howie Hua) 1665353677

OK, seriously. That is way easier to do in your head. It's basically putting the numbers into expanded form and adding them, which makes it easier to visualize.

Adding this way makes sense, but subtracting is a bit more complicated, right?

Wrong, apparently. Watch Hua work his math sorcery subtracting two and three-digit numbers.

@howie_hua
Did you know you can subtract left to right? #math #mathematics #mathtok #maths #teachersoftiktok #teacher #mathtricks #mathtrick

Holy moly. That's faster than the right-to-left, borrow-from-the-next-column method, isn't it? And again, so much easier to visualize what's actually happening, though I don't know if I could fully do this in my head like I could with the left-to-right addition.

Hua recently shared another cool subtraction trick for problems with minuends that have a lot of zeroes. (The minuend is the first number in a subtraction problem. Don't be too impressed. I had to look it up.)

Check this out:

@howie_hua
An underrated subtraction strategy #math #mathematics #mathtok #maths #teachersoftiktok #teacher #mathtricks #mathtrick

So simple, so time-saving and so something I would never have figured out on my own.

These tips and tricks might come in handy for anyone, but they're especially useful for kids who are having to do these kinds of math problems at school all the time. Even if they're supposed to solve the problem with a different strategy, these methods can be a quick way to check their answers.

Anything that makes math easier, I say. You can watch Hua's videos on TikTok, YouTube and Twitter.

This article originally appeared on 10.12.22

From Your Site Articles

Pop Culture

People are busting out calculators to check this seemingly impossible math equation

This math isn't mathing.

Photo credit: Canva

It's math that's simple enough for a third grader, but it seems wrong no matter how you calculate it.

Time is a strange phenomenon. It speeds up when we want it to slow down and drags when we wish it would go by faster. Sometimes it feels like we blink and a decade has gone by. Cue "the days are long, but the years are short," "time flies when you're having fun," and all the other time cliches that feel 100% true.

Of course, those truisms are all about our perception of time, not time itself. Time ticks by in a never-changing rhythm of seconds, minutes, hours, days and years, perfectly metered and measured. But it sure doesn't feel that way, which is why a simple math equation an average third grader can do has grown adults pulling out their calculators to make sure it's correct.

The equation in question comes from meme that reads "1981 and 2024 are as far apart as 1981 and 1938."

Yep, it's correct. The math checks out, no matter how many times you plug the numbers into the calculator. So why does it feel so wrong?

Again, time is a tricky thing. Those of us who were alive in 1981 remember how far back 1938 seemed to us at that time, and there's simply no way that distance is what 1981 is to us now. It seems impossible.

Part of the problem is that, at least for the middle-agers among us, the 80s still feels like they happened 20 years ago, not 43. That's simply how time perception works as we age.

But that's not all of it. As some people have pointed out, there were certainly major changes in both time periods, but the hugely significant cultural changes from 1938 to 1981 were more visible in many ways than most changes we've seen since then. Yes, technology exploded near the turn of the millennium, but once the internet and laptops and smartphones hit the scene, tech advancements have mostly been a matter of degree—better, smaller, lighter, faster, more efficient, more intuitive—in fairly steady increments and not so much dramatic jumps.

From 1938 to 1981, we saw huge leaps, from tiny black-and-white television to full-color cable television, from the first transatlantic passenger flight to sending humans to the moon on space shuttles, from switchboards and party lines to cell phone technology, from human computers to PCs.

We also saw clothing styles change drastically from one decade to the next during that time period in a way that we haven’t really seen in the past 40 years. Same with architecture and home designs. The mid-20th century saw the birth of rock n' roll, the Civil Rights Movement and the shift to women into the workforce. Again, huge leaps.

Wars also defined generations more in the mid-20th century than in the decades since, from WWII to the Vietnam War to the Cold War. It’s not that we haven’t had wars since 1981, but the direct impact of those wars on American life has not been as notable as those previous wars were.

Then again, it’s possible that much of the difference in feel is simply our perception of life now vs. then. Do the years since 1981 seem shorter simply because we’ve lived them, whereas most of us weren’t alive for a good chunk of the 1938 to 1981 time period and only learned it as “history”?

Hard to say, but one thing that’s clear is that people do not like the way this math feels, as evidenced by the comments people left on the post.

“Fitz is cancelled. Feeling triggered here. Lol”

“I did the math too many times because I don’t want to believe this.”

“As someone born in 1981 I really dislike this.”

“Shut your mouth. Those are fighting words! “

“I honestly did nothing to you! Like why?”

“They're not far apart. You're far apart."

It certainly will be interesting to see how the next 43 years feel for the people who live through it vs. 1981 until now.

From Your Site Articles

time

Family

A study has been following 'gifted' kids for 45 years. Here's what we've learned.

Some of what we used to think about gifted kids turned out to be wrong.

What can we learn from letting seventh graders take the SAT?

In the 1960s, psychologist Julian Stanley realized that if you took the best-testing seventh graders from around the country and gave them standard college entry exams, those kids would score, on average, about as well as the typical college-bound high school senior.

However, the seventh graders who scored as well or better than high schoolers, Stanley found, had off-the-charts aptitude in quantitative, logical, and spatial reasoning.

In other words, they were gifted.

In the 1970s, Stanley and his team launched a full-scale study, identifying many of America's gifted kids and tracking them throughout their lives.

The study, called the Study of Mathematically Precocious Youth never ended and is now nearly 45 years in the making. It has followed countless kids from middle school into their careers as some of America's top politicians, scientists, CEOs, engineers, and military leaders.

Stanley passed away in the mid-2000s, but psychologist David Lubinski helped bring the study to Vanderbilt University in the 1990s, where he now co-directs it with Camilla P. Benhow.

It's not a stretch to call this the biggest and most in-depth study on intellectual "precociousness." The results of the study thus far are equal parts fascinating and genuinely surprising — a deeply insightful look into the minds and lives of brilliant children.

1. Some of what we used to think about gifted kids turned out to be wrong.

Ever heard the saying "early to ripe, early to rot"? It basically means doing "too much" to foster a kid's special talents and abilities at too young an age could actually cause harm in the long term.

That's not even remotely true, at least not according to Lubinski.

That might be an outdated example. But Lubinksi says there are plenty of other misconceptions still alive today, like the idea that gifted kids are so smart that they'll "find a way" to excel even if those smarts aren't nurtured and developed.

Not so fast. "They're kids," he explains. "They need guidance. We all need guidance."

2. Intelligence is not the same as passion.

Quick, what's the "smartest" career you can think of. Doctor? Scientist?

While you do have to be pretty brilliant to work in medicine or science, those are far from the only career paths gifted kids choose later in life.

"Quantitatively, gifted people vary widely in their passions," Lubinski says. Many of the students in the study did end up pursuing medicine, but others went into fields like economics or engineering. Others still were more gifted in areas like logical or verbal reasoning, making them excellent lawyers and writers.

"There are all kinds of ways to express intellectual talent," Lubinski explains.

When it comes to doing what's best for a gifted student, it's just as important for parents and educators to know what the student is passionate about rather than pigeonholing them in traditionally "smart" fields and registering them in a bunch of STEM courses.

3. Hard work definitely still matters.

Measuring a student's aptitude, their natural abilities, is only one part of the equation when it comes to determining how successful they'll be in life. Aptitude scores can identify a particularly strong natural skill set but tell us very little about how hard that person might work to excel in that field.

Effort, Lubinski says, is a critical factor in determining how far someone's going to go in life. "If you look at exceptional performers in politics, science, music, and literature, they're working many, many hours," he says.

(And for the record, there are a lot more important things in life than just career achievement, like family, friends, and overall happiness.)

4. Regardless of aptitude, every kid deserves to be treated as though they were gifted.

The study's focus is specifically on kids within a certain range of intellectual ability, but Lubinski is careful to note that many of its findings can and should be applied to all students.

For example, the kids in the study who were given an opportunity to take more challenging courses that aligned with their skills and interests ultimately went on to accomplish more than the students who were not afforded the same opportunity.

"You have to find out where your child's development is, how fast they learn, what are their strengths and relative weaknesses and tailor the curriculum accordingly," Lubinski says. "It's what you would want for all kids."

It may sound a bit like a pipe dream, but it's a great starting point for how we should be thinking about the future of education in America.

If you'd like to learn more about the Study of Mathematically Precocious Youth, check out this short film on the project created by Vanderbilt University:

Quick Learners; High Achievers: Study of Mathematically Precocious Youth

This article originally appeared on 09.22.17

From Your Site Articles

Education

Watching kids do lightning fast mental math is both mesmerizing and mind-blowing

Their finger twitching looks random, but WOW is it impressive.

Digamarthi Sri Ramakanth/Wikimedia Commons

2003 UCMAS National Abacus & Mental Arithmetic Competition

In the age of calculators and smartphones, it's become less necessary to do math in your head than it used to be, but that doesn't mean mental math is useless. Knowing how to calculate in your head can be handy, and if you're lucky enough to learn mental abacus skills from a young age, it can be wicked fast as well.

Video of students demonstrating how quickly they can calculate numbers in their head are blowing people's minds, as the method is completely foreign for many of us. The use of a physical abacus isn't generally taught in the United States, other than perhaps a basic introduction to how it works. But precious few of us ever get to see how the ancient counter gets used for mental math.

The concept is simple and can be taught from a young age, but it takes a bit of time and practice to perfect. Watch what it looks like for basic addition and subtraction at lightning speed, though:

See on Instagram

If you don't know what they're doing, it looks like students are just randomly flicking their fingers and wrists. But they are actually envisioning the abacus while they move their fingers, as if they were actually using one.

There are various methods of finger calculations that make use of abacus concepts. Watch another method that uses both hands in action:

— (@)

Even very young children can calculate large sums very quickly using these abacus-based mental math methods. Watch these little superstars add two-digit to four-digit numbers like it's nothing.

How do they do it?

Much of the skill here requires a solid understanding of how an abacus is used to calculate and lots of practice with the physical movements of calculating with it. That's not exactly simple to explain, as it take a couple of years of practice using an abacus—for these mental calculations, specifically the Japanese soroban abacus—to gain the skills needed to be able to calculate quickly. BBC Global shares how such practices are taught in Japan, not only for mental math but for overall cognitive memory:

Abacus mental math programs online recommend learning it between the ages of 5 to 13. It is possible to learn at older ages, but it might take longer to master compared to younger students.

But if there's a finger method you want to try for addition and subtraction up to 99, one that's simple and quick to learn is called chisanbop, in which ones are counted on one hand and 10s are counted on the other. Here's an explainer video that shows how it works:

Chisanbop!

Most of us carry calculators around in our pockets with us at all time, so such practices may feel like a waste of time. But learning new skills that tax our brain is like a workout for our mind, so it's not a bad idea to give things like this a spin. Even if we don't learn to calculate large numbers in the blink of an eye, we can at least exercise our mental muscles to keep our brains healthier. And who knows, maybe we'll get a party trick or two out of it as well.

From Your Site Articles

education

Science

Pick a random number between 100. You probably chose 37, and there's a big reason for that.

Why are people seeing the number everywhere?

via Veritasium/YouTube

Why is number 37 everywhere?

When we think of randomness, something chaotic and unpredictable often comes to mind. The funny thing is that when people are asked to choose a random number between 1 and 100, they will most reliably select 37. That doesn’t feel very random.

So why do people seem to have a strange subconscious affinity for such a seemingly random number? Derek Muller and his team at Veritasium investigated this intriguing phenomenon in a video entitled, “Why is this number everywhere?”

To unravel the mystery surrounding 37, Veritasium surveyed 200,000 people, asking them to select a random number. The ones that came up most often were 7, 73, 77 and 37.

Participants were then asked to choose a number they thought would be the least selected. Setting aside the extreme values and the number 50 for being positioned centrally, the numbers that emerged as the most chosen were 73 and 37, almost at a tie.

In reality, the least-selected numbers were 90, followed by 30, 40, 70, 80, and 60.

Why is this number everywhere?

One reason why people choose 37 is because it’s a prime number. Muller says that primes “feel like the most random numbers,” adding that they “don’t appear that much in our lives.” The show’s director Emily Zhang, noted that as a child, she had a book that counted to a hundred and it had a story for every number, but it had little to say about 37.

“So for 26, that's how many letters in the alphabet,” Zhang said. “Or for 30, they give the days of September. Or for 52, that's how many cards are in a deck.” But there isn’t anything notable about 37 besides the fact that it’s a prime number. The fact that little is attached to the number gives it an extra quality of randomness.

On a deeper level, the number 37 seems to coincide with how we’re wired to make decisions when choosing from a large number of options.

Using some rather complex math, Muller demonstrates that when people are given a large number of choices, they will explore and reject 37% of them to get a sense of what's available. They will then elect the first option that's better than all of the ones they’ve seen.

Muller used how we choose partners to give an example of how this works.

“So if you want to get married, say, in 10 years, then spend the first 3.7 years seeing what's out there and then select the next person who's better than anyone you've seen,” Muller says.

The video does a great job of revealing people's blind spots when they try to be random. It’s a lot like when parents choose a unique baby name, but on the first day of kindergarten, they realize other people had the same “unique” idea.

“We can argue special coincidences for many numbers, but we need to finally address the elephant in the room,” Muller concludes the video. “The sheer amount of brain power 37 secretly takes up in our collective minds. It's humanity's go-to random number, one of our most prominent prime numbers, and most of all, our ideal number for making decisions. Maybe that's why we're inclined to it naturally. It feels right to us as where to settle and what to pick.”

Now that you’ve seen this video, you’ll probably see 37 everywhere.

From Your Site Articles

math

Science

Fascinating video explains a truth bees intuitively know: 'hexagons are the bestagons'

CGP Grey/YouTube

Hexagons are the best of all polygons.

"What's your favorite shape?" is generally a question we ask 5-year-olds, not grown adults. But maybe if we put it into more advanced terms—"What's the best polygon?"—we'd be compelled to give it some genuine thought.

Since there's an entire field of math dedicated to triangles, that might seem like a logical answer. But, most human-made things around us are made up of rectangles, so maybe they're the best. Then again, there are much more interesting quadrilaterals than squares and rectangles (hey, rhombus!) in addition to pentagons, hexagons, heptagons (which I don't think I've ever even seen), octagons, nonagons—so many "gons" to choose from.

As it turns out, there is an answer to this question—at least according to popular YouTube creator CGP Grey.

The answer? Hexagons. Who knew, right?

If you have doubts that the six-sided shape deserves the title of "best," CGP Grey's video might change your mind.

In it, we see how bees use hexagons to make honeycomb. That's not by accident; it's because hexagons are actually the most efficient shape for tiling. It's the same reason bees' eyes are made up of tons of tiny hexagons—and why the back of our eyes are too.

Snowflakes have six sides, which alone is reason enough for the hexagon to be the bestagon, but the reason they're six-sided is super cool. Saturn has a mysterious, humongous hexagon of gases the size of six Earths, which is weird but also super cool.

But that's just the peripheral stuff. There's a fundamental atomic reason why hexagons are the bestagons—strength and stability which allows hexagons to create the strongest atomic material in the universe.

And, of course, Settlers of Catan.

If you have doubts, let CGP Grey convince you. By the end, you'll have to at least admit that hexagons are pretty darn cool, even if you're partial to some other polygon.

From Your Site Articles

30 years after retiring, this 89-year-old math teacher hasn't stopped helping students

GMA/YouTube

Delores Spencer has been teaching math since 1954. When she retired from her Virginia school district 30 years ago, she started tutoring students and hasn't stopped. Now, at age 89, even in the midst of a global pandemic, Mrs. Spencer is still going strong.

Mrs. Spencer has kept up her teaching skills through her decades since retirement, even learning the new ways math gets taught. And when in-person tutoring got thwarted by COVID-19, she took it as an opportunity to reach more people through virtual tutoring.

Since last spring, Mrs. Spencer has provided math lessons online through her Math Lab on Facebook and YouTube. Each week, she posts a free, hour-long lesson on a particular math concept to help students and parents learn better.

"I just really wanted to help students get over that fear of math," Spencer said in a video interview with Good Morning America. "So many parents and students have fear of mathematics. And it really, it's beautiful."

She said she wants to reach people who need tutoring but can't afford it. "If I can find out what blocks you, then I can remove that block, and usually you don't need me anymore until you get to another block. And that's what real tutoring is about."

Watch this inspiring woman in action:

89-year-old math tutor's virtual lessons reach students around the world l GMAwww.youtube.com

Thank you, Mrs. Spencer, for showing us that we don't have to stop doing what we love just because we get older, and for continuing to share your gift of teaching with the world.

From Your Site Articles

math

Math professor shows how adding and subtracting left to right is actually easier and faster

Mind. Blown.

A study has been following 'gifted' kids for 45 years. Here's what we've learned.

Some of what we used to think about gifted kids turned out to be wrong.

What can we learn from letting seventh graders take the SAT?

In the 1970s, Stanley and his team launched a full-scale study, identifying many of America's gifted kids and tracking them throughout their lives.

1. Some of what we used to think about gifted kids turned out to be wrong.

2. Intelligence is not the same as passion.

3. Hard work definitely still matters.

4. Regardless of aptitude, every kid deserves to be treated as though they were gifted.

Quick Learners; High Achievers: Study of Mathematically Precocious Youth

Watching kids do lightning fast mental math is both mesmerizing and mind-blowing

Their finger twitching looks random, but WOW is it impressive.

Chisanbop!

Pick a random number between 100. You probably chose 37, and there's a big reason for that.

Why are people seeing the number everywhere?

Why is this number everywhere?

Fascinating video explains a truth bees intuitively know: 'hexagons are the bestagons'

30 years after retiring, this 89-year-old math teacher hasn't stopped helping students

Researchers dumped tons of coffee waste into a forest. This is what it looks like now.

Naming twins is an art. Here are some twin names people say are the best they've ever heard.

5-year-old gave his mom advice for handling nerves. It was both adorable and spot-on.

Two brothers Irish stepdancing to Beyoncé's country hit 'Texas Hold 'Em' is pure delight

Family posts a very chill note to neighbors explaining why their dog is on the roof

Cat owner put a first person camera on their collar and accidentally filled the world with delight