### June 24 – Big Numbers Day

Posted on June 24, 2016

I decided to talk about big numbers because of the following historical anniversaries:

• On this date in 2003, a manuscript by author Georges Simenon sold for \$325,579.
• On this date in 2002, one of Monet's Waterlilies paintings sold for \$20.2 million.
• On this date in 1998, Walt Disney World Resort admitted its 600 millionth guest.
• Also on this date in 1998, AT&T bought cable TV company Tele-Communications, Inc., for \$31.7 billion.

I wrote them in this order to go from smallest to largest of the big numbers. But the big numbers are written in different formats – so it is harder to see how they relate to one another.

Here the numbers are written ONLY with numerals, no words:

325,579

20,200,000

600,000,000

31,700,000,000

Yikes, those numbers are big!

But they aren't as big as the numbers that scientists use! Those thousands, millions, and billions are swamped by the trillions and sextillions and decillions and much, much greater numbers!

That's partly because the universe is really, really, really, really huge! And because the universe is made up of things that are really, really, really tiny.

It's also partly because networks - like the network made by all of the interconnected neurons in our brain, and like the internet (pictured here, right) - end up with large numbers of connections and nodes.

Here are some examples of how we might use those numbers:

• the nearest star to our sun (Sol), Alpha Centauri, is more than 26 trillion miles away: 26,000,000,000,000
• the entire Earth has about 326 quintillion gallons of water: 326,000,000,000,000,000,000
• the volume of the Earth is about 1.085 sextillion cubic meters: 1,085,000,000,000,000,000,000
• one liter of water contains about 33.4 septillion water molecules: 33,400,000,000,000,000,000,000,000
• the volume of the sun is about 1.412 octillion cubic meters: 1,412,000,000,000,000,000,000,000,000
• the mass of the sun is about 1.989 nonillion kilograms: 1,989,000,000,000,000,000,000,000,000,000
• the area of the Milky Way galaxy is about 702 decillion square kilometers: 702,000,000,000,000,000,000,000,000,000,000,000

You probably know that scientists use exponents to express large numbers: for example, 702 * 10^33, or 7.02 * 10^35.

• Have fun with Math Cats. Just type in a really large number and then see how to write it. I got one decillion!
•  A million pennies is...a LOT!
Can you figure out how many dollars a million pennies are worth? Answer below...
The MegaPenny Project is designed to help you better picture large numbers. Check it out.

(ANSWER: One million pennies is worth ten thousand dollars)

Also on this date:

Inti Raymi (Sun Festival) in Peru