Top Ten numbers

1. Pi

Pi. It’s the only number to have its own holiday. Math teachers worldwide seem to own a countless array of pi-themed t-shirts and other memorabilia.

But what is pi? And why is it so famous? The simple explanation of what pi is has to do with a circle. Pi or 3.14159265… is the ratio of the circumference of a circle divided by its diameter.

Pi is also really old. While it’s hard to pin down exactly when the modern pi, 3.14 that is, was first approximated, we do know that various ancient civilizations from the Egyptians to the Chinese to the Indians to the Greeks all had various approximations of pi that were very close to the modern value we use today.

If you’ve ever wanted to see 1 billion digits of pi, follow this link.

2. Phi

Phi is like pi except it has an extra h. Despite being lesser known than its irrational cousin, phi too is a ratio that describes the relationship that is best explained by the graphic below.

Phi is the name for the constant that describes the golden ratio which is often found in nature, music, architecture and the arts.

Phi also relates to the Fibonacci sequence as phi emerges as consecutive numbers in the sequence are divided.

3. e

The number e is the third irrational constant on the list and is often used when dealing with logarithms, exponentials and problems dealing with compound interest.

But the reason that e is one of my top 10 numbers is the following: there’s an equation in math called Euler’s identity that’s really cool. It combines some of the numbers of the list into one simple, clean formula shown below.

If you want to know how this actually equals 0, well you’re in luck. If you take Calculus BC with Mr. Kaim, he’ll show and you’ll probably think it’s really cool, but then forget how it actually works when it comes time to write about in the DGS Blueprint.

4. i

Next a number so cool, it doesn’t exist. That’s right, it’s imaginary. The number i is defined as the square root of -1. If you’re confused by the square root of a negative, you’re not alone. The introduction of i to math students inevitably leads to students questioning if all the math they’ve been taught is a lie.

5. Zero

Zero? Why is zero on this list? Well, while zero may seem commonplace and obvious to us today, it wasn’t always that way. Initially when zero was used as a placeholder, it was signified with an empty space. This allowed numbers such as 2,025 to be differentiated from 225.

However, it wasn’t until the ancient Indians first started using zero as a mathematical number—zero was independently “discovered” by other civilizations such as the Mayans. The advent of zero as a true mathematical idea brought forth rapid developments in math. Eventually the concept of zero spread to the Middle East where it allowed for the creation of the algebra we all know and love today.

6. 2

Two is a really cool number. It’s even, but it’s prime. Two squared, two plus two and two times two all equal the same number. Two is the number we use to double numbers. I don’t have much more to say about two except that it’s pretty cool.

7. Tau

Tau? What is tau? I wasn’t really sure before I started looking for cool numbers for this list, but now I can tell you why it deserves to come in at number seven on the list of best numbers. First, it’s fun to say. Just say it. Tau. Second, it has been proposed that tau be defined as 2π. This would make trigonometry a lot easier as the circumference of the unit circle now would have a cool new name.

8. -1

Negative one is like one, but it’s negative. Negative numbers are pretty cool because they’re like positive numbers, but everything is reversed. Subtract a negative, you’re going right on a number line. Multiply two negatives together, that’s a positive. If you don’t think that’s cool, you probably stopped reading this article a long time ago.

9. Root 2

Root two is number nine on this list. Root two appears in a variety of areas. It’s the hypotenuse of a right triangle with sides the length of one. It also makes an appearance in trigonometry. The height of the 45 degree angle of a triangle in the unit circle is half of the value of root two. Root two is cool no matter how you look at it.

10. 17

Why is 17 on this list? Well, it’s my favorite number. I don’t really know why, but it is. I like the way it looks I guess. If you were to ask me if there were any athletes that wore 17 that I look up to, I couldn’t really tell you. But all I can tell you is that it’s my favorite number.