A PERSONAL MESSAGE FROM UPWORTHY
We are a small, independent media company on a mission to share the best of humanity with the world.
If you think the work we do matters, pre-ordering a copy of our first book would make a huge difference in helping us succeed.

# math

Education

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

### Mind. Blown.

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."

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.

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?

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.

Science

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

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.

Videos

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

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.