Archives: Startling Statistics
Fun Facts and Number Trivia
Math Gym 2012-13
1. The fastest person in the world, Usain Bolt of Jamaica, ran 100 meters (about 328 feet) at the London Olympics in just 9.63 seconds. How many feet per second is that? How many feet per second do you think you can run? (Does it matter how far you're going?) Measure and see how fast you can go! Interested in finding out how Usain Bolt compares to the fastest runners in history, or to the world’s fastest kids? Check out this neat video from the New York Times to find out.
2. There are over 12,000 species of ants, and they live on every continent except Antarctica. A single acre of Amazon rainforest can house 3.5 million ants! Scientists estimate that ants outnumber humans on earth by more than 1.5 million to 1. The current human population of the world is approximately 7 billion. What would you expect the ant population to be?
3. Paper used to be made out of linen and cotton. In the 1840s it started being made out of wood. Now, roughly 100 million trees a year are used just for making junk mail in the United States. Worldwide, about 27,000 trees are used daily just for toilet paper! If an average tree can be made into about 8300 sheets of paper, can you estimate how many trees your school uses for the homework and notices it sends home over the course of a year?
4. Pluto was considered a planet from its discovery in 1930 until 2006, when it was demoted to "dwarf planet" due in part to its small size. The diameter of Pluto, just over 2300 km or about 1430 miles, is small enough that it would almost fit within the United States! Check out this amazing comparison of how Pluto, the United States, and many other things in our universe, from the unimaginably small to the astronomically big, compare to one another.
5. 1 billion = 1,000,000,000 (one with 9 zeros)
1 quintillion = 1,000,000,000,000,000,000 (one with 18 zeros)
A person has about 100 billion brain cells. There are 7 billion people presently living on earth.
The "brain" of a computer is made up of transistors. It's been predicted that by 2015, the number of transistors in the world will exceed 1,200 quintillion. How will that compare to the number of braincells of all the humans on planet earth?
1 quintillion = 1,000,000,000,000,000,000 (one with 18 zeros)
A person has about 100 billion brain cells. There are 7 billion people presently living on earth.
The "brain" of a computer is made up of transistors. It's been predicted that by 2015, the number of transistors in the world will exceed 1,200 quintillion. How will that compare to the number of braincells of all the humans on planet earth?
6. Next time you're feeling lonely, take comfort in the fact that you've actually got trillions of tiny creatures for company! "Microbes" are microscopic life forms including bacteria, fungi, protozoa, and viruses. Some are harmful to people (we typically call them "germs") but many are not, and some are actually good for us and important for our good health. We have a lot more of them in our bodies than you might think! On a person's body there are 10 times more bacterial cells than human cells, and an adult can have up to 10 trillion bacteria in his gut alone.
7. People grow 20 baby teeth, which are eventually replaced by 32 adult teeth. Lots of animals, including birds, turtles, some whales, and pangolins, have no teeth at all. The narwhal, a type of whale that lives in the arctic, has exactly two teeth, both in its top jaw. One of those two teeth can grow to 9 feet long, but the other one usually stays small. Some types of dolphins have up to 250 teeth. Sharks, which have many rows of teeth, keep shedding and replacing them, and can have thousands of teeth over their lifetimes. Whale sharks can have a whopping 3000 teeth at one time (though they're small and not very useful).
Kate has 30 teeth. She spends two minutes brushing them each morning. At that rate, how long would it take to brush all the teeth of a whale shark?
Kate has 30 teeth. She spends two minutes brushing them each morning. At that rate, how long would it take to brush all the teeth of a whale shark?
8. "Chain letters" (or emails) sometimes urge each person who reads the letter to forward it to ten friends. Each of those friends is asked to forward it to ten more friends, and so on.
Imagine that on January 1st of this year a chain letter is sent to one person. The next day, that person sends it to 10 people. The next day, each of those people sends it to 10 more people, and so on. If each day, every new recipient sends the letter to 10 people who haven't received it yet (and if each recipient receives it in time to forward it to 10 new people the next day), by what date would the entire world's population of about 7 billion people have received it?
Imagine that on January 1st of this year a chain letter is sent to one person. The next day, that person sends it to 10 people. The next day, each of those people sends it to 10 more people, and so on. If each day, every new recipient sends the letter to 10 people who haven't received it yet (and if each recipient receives it in time to forward it to 10 new people the next day), by what date would the entire world's population of about 7 billion people have received it?
9. Want to discover a new species? Try looking in the ocean. The world's oceans cover about 140 million square miles, more than 70% of our planet's surface. But people have explored only a tiny portion of those oceans so far -- just a little more than 5%. Imagine how much there is still to discover! So far, scientists have discovered between 2 and 3 hundred thousand species of ocean plants and animals. By one recently published estimate, that may be only about a third of all the species that actually live there. If that estimate is correct, how many species would live in the oceans altogether? That would be a lot of species still to find, study, and name!
Math Gym 2011-12
1. If you could fold a regular piece of paper in half 42 times, it would be thick enough to reach the moon.
When you keep doubling things, they get big really fast! But you can't really fold paper 42 times: it quickly gets too thick to fold. Good thing, or it wouldn't fit in your house! How many folds can you make?
When you keep doubling things, they get big really fast! But you can't really fold paper 42 times: it quickly gets too thick to fold. Good thing, or it wouldn't fit in your house! How many folds can you make?
2. A radio broadcaster's voice can be heard sooner by someone thousands of miles away than by someone who is standing in the back of the room in which the broadcaster is speaking.
Wondering why? Radio waves travel at the speed of light: about 186,000 miles per second. Sound, which travels much more slowly, takes about 5 seconds to travel just one mile. (Knowing the speed of sound can also help you figure out how far away lightning is: for every 5 seconds between when you see lightning and when you hear thunder, the lightning is approximately one mile away.)
Wondering why? Radio waves travel at the speed of light: about 186,000 miles per second. Sound, which travels much more slowly, takes about 5 seconds to travel just one mile. (Knowing the speed of sound can also help you figure out how far away lightning is: for every 5 seconds between when you see lightning and when you hear thunder, the lightning is approximately one mile away.)
3. The record-holding person has memorized 100,000 digits of pi. (Computers have calculated pi to the first 5 trillion digits.)
Pi is a number a little bigger than 3. It is special enough to have its own nickname because it's the answer you get when you divide any circle’s circumference (the distance around the outside of the circle) by its diameter (the distance across the circle, passing through its center). How much of pi can you remember? Click here to see the first 100,000 digits. Want a trick to remember the first ten? They’re the number of letters in the words in the following two sentences: “May I have a large container of coffee? Thank you.” (3.141592653) Some people have written other sentences, or even whole stories, to help them remember the digits of pi. Can you create one?
Pi is a number a little bigger than 3. It is special enough to have its own nickname because it's the answer you get when you divide any circle’s circumference (the distance around the outside of the circle) by its diameter (the distance across the circle, passing through its center). How much of pi can you remember? Click here to see the first 100,000 digits. Want a trick to remember the first ten? They’re the number of letters in the words in the following two sentences: “May I have a large container of coffee? Thank you.” (3.141592653) Some people have written other sentences, or even whole stories, to help them remember the digits of pi. Can you create one?
4. In chess, there are 20 possible moves for white's first turn (each pawn could move either one or two spaces and each knight has two possible moves). For each of those 20 possible moves, black then has 20 possible moves of his own, making 400 possible combinations even by the time each player has only had one turn. Then other pieces start being able to move, too. Over the course of an entire chess game, there have been estimated to be more possible combinations of moves than there are atoms in the observable universe.
5. Can you count to a billion? Not by ones starting at 1, you can't! Here's why: You can say a 1-digit number in less than a second, but a 9-digit number takes a while to say. Assume that it takes an average of about 4 seconds to say each number. If you started counting at age 10 and continued until you were 70, even if you took no breaks at all (even to sleep), you wouldn't even get to half a billion.
How far would you get if you only counted for an hour a day?
How far would you get if you only counted for an hour a day?
6. One million $1 bills, piled on top of each other, would be taller than a 30-story building (each is .0043 inches thick). They would weigh about as much as a small car (each weighs one gram).
How many miles would they stretch if you laid them end-to-end? (Each is 6.14 inches long.)
How many miles would they stretch if you laid them end-to-end? (Each is 6.14 inches long.)
7. A rhinoceros beetle can lift 850 times its own weight, making it the strongest of all the animals for its size.
How much do you weigh? If you were as strong for your size as a rhinoceros beetle is, what animals would you be able to lift? Take a guess, then calculate and see!
Some typical animal weights:
Grizzly bear: 500 pounds
Hippopotamus: 5,000 pounds
African elephant: 11,000 pounds
Gray whale: 43,000 pounds
Sperm Whale: 68,000 pounds
Blue whale: 240,000 pounds
How much do you weigh? If you were as strong for your size as a rhinoceros beetle is, what animals would you be able to lift? Take a guess, then calculate and see!
Some typical animal weights:
Grizzly bear: 500 pounds
Hippopotamus: 5,000 pounds
African elephant: 11,000 pounds
Gray whale: 43,000 pounds
Sperm Whale: 68,000 pounds
Blue whale: 240,000 pounds
8. Cheetahs get all the credit, but they can only go about 70 mph at their fastest. The peregrine falcon can fly up to 217 mph! The very fastest humans have only run about 27 mph.
How fast are you? How could you measure your own running speed?
How fast are you? How could you measure your own running speed?
9. Have you ever used a cricket thermometer? The frequency of a cricket's chirps is related to the temperature. Count the number of chirps in 14 seconds and add 40 to get a rough estimate of the temperature in Fahrenheit.
10. The hottest day ever recorded was 136 degrees (in Libya in 1922). The lowest was -128.6 (in Antarctica in 1983). So how big of a range of temperatures is there on earth? Be glad you don't live on Mercury, where it would be hard to pack the right clothes for all possible changes in temperature. Mercury has a temperature range of over a thousand degrees! Its very thin atmosphere makes its temperature vary wildly, from about -300 degrees Fahrenheit at its coldest to about 870 degrees Fahrenheit at its hottest (hot enough to melt some metals!).
11. Although it’s in a frequency too low for people to hear, a blue whale can make a sound so loud that it can be detected 500 miles away.
Human ears can only detect sounds that are in a fairly narrow range. Kids can usually hear higher-pitched sounds than adults can. Try competing against your parents to see who can hear the highest frequency (you'll probably win!). Some animals can hear (and communicate in) much higher or lower pitches than people can. Curious to learn more about sound? Try this site for lots of information and activities.
Human ears can only detect sounds that are in a fairly narrow range. Kids can usually hear higher-pitched sounds than adults can. Try competing against your parents to see who can hear the highest frequency (you'll probably win!). Some animals can hear (and communicate in) much higher or lower pitches than people can. Curious to learn more about sound? Try this site for lots of information and activities.
12. George Parker Bidder learned to count when he was 5 or 6, and then taught himself how to multiply by arranging lead pellets in rectangular arrays. By the time he was 8 years old, he could multiply any two numbers, of up to six digits each, in seconds -- in his head!
Want some tips to become an arithmetic speed demon yourself? Try here.
Want some tips to become an arithmetic speed demon yourself? Try here.
13. The "Big Dig", a project to move some of the traffic that used to go through downtown Boston into tunnels below ground, used enough concrete to make a 3-foot wide and 4-inch thick sidewalk from Boston to San Francisco … and back … and then back to San Francisco again!
How could you figure out approximately how much concrete that was? (San Francisco is approximately 2700 miles from Boston.)
How could you figure out approximately how much concrete that was? (San Francisco is approximately 2700 miles from Boston.)
14. Did you know chimpanzees not only can put the numerals 1-9 in order, but can do it faster than a person can? Chimpanzees and humans were briefly shown numerals from 1-9 in a mixed up order on a computer screen. The numerals disappeared and were replaced by empty boxes, and the challenge was to remember which digit was where and push the boxes in ascending order. The chimpanzees were much faster than the humans in the experiment.
Want to see if you can keep up with the chimp? Bet you can’t!
Want to see if you can keep up with the chimp? Bet you can’t!
15. The average human body contains more than 60,000 miles of blood vessels!
If you could straighten them out and lay them end to end, how many times would they go around the earth's equator? (The circumference of the earth at the equator is about 25,000 miles. The earth is not actually a perfect ball, so it's slightly wider at the equator than if you go around the poles.)
If you could straighten them out and lay them end to end, how many times would they go around the earth's equator? (The circumference of the earth at the equator is about 25,000 miles. The earth is not actually a perfect ball, so it's slightly wider at the equator than if you go around the poles.)
16. Over a lifetime, the average person will spend about 26 years asleep, and about three years using the bathroom.
Can you estimate how much of your life you'll spend brushing your teeth? At school? Watching TV?
Can you estimate how much of your life you'll spend brushing your teeth? At school? Watching TV?
17. A "googol" is a 1 with 100 zeros after it. It is more than the number of grains of sand in the world. A "googolplex" (10 to the power of a googol) is such a big number that if you wrote it down it would take up more space than the length of the universe, and would take more time than the age of the universe to write it.
The words were invented by a 9-year-old. He thought a googolplex ought to mean a 1 followed by as many zeros as a person could write until they were tired. His mathematician uncle thought it would be better to be a little more specific. If you were inventing a special nickname for a number, what number would it be? What name would you give it?
The words were invented by a 9-year-old. He thought a googolplex ought to mean a 1 followed by as many zeros as a person could write until they were tired. His mathematician uncle thought it would be better to be a little more specific. If you were inventing a special nickname for a number, what number would it be? What name would you give it?
18. Next time your parents complain about the cost of gas, ask them which they think is more expensive, gas or single servings of bottled water. At the time this paragraph was written, a liter of bottled water was listed at one local store as $1.89. That comes out to more than $7 per gallon. During that same week, gas in Lexington cost nearly $4 per gallon. At those prices, how much more would it cost to fill a minivan’s 20-gallon tank with bottled water than with gas?
19. The population of the world is currently over 7 billion. Just 100 years ago, it was less than 2 billion. 500 years ago, it was probably only about 450 million. It's been estimated that the number of people who ever lived is approximately 108 billion. Can you figure out what percentage of all the people who ever lived are alive today?
20. Want to visit a star someday? Besides our own sun, the nearest star to earth is Proxima Centauri. Proxima Centauri is 4.22 light years from earth, which means if you were a beam of light it would take you 4.22 years to get there. But people travel more slowly than light. The fastest outward-bound spacecraft so far, Voyager 1, left earth in September 1977 and has been traveling ever since. In that time, it has made it farther than any other man-made object, nearing the edge of our solar system -- but still nowhere near any other star. Voyager 1 travels at about 1/18000 the speed of light. At that speed, how long would it take a spaceship to get from Earth to Proxima Centauri?