169,518,829,100,544,000,000,000,000,000 ways to play the first ten moves in a game of chess!
111,111,111 x 111,111,111 = 12,345,678,987,654,321
10^−360,783 is the probability that a monkey could write Hamlet in one go, including capitals and punctuation. Source
A 'jiffy' is an actual unit of time for 1/100th of a second.
1 and 2 are the only numbers where they are the values of the numbers of factors they have.
'Forty' is the only number that has all its letters in alphabetical order.
'FOUR' is the only number in the English language that is spelt with the same number of letters as the number itself
Multiply 37,037 by any single number (1-9), then multiply that number by 3. Every digit in the answer will be the same as that first single number.
1x9 +2 = 11 , 12x9 +3 = 111 , 123x9+4 = 1111 etc
2 and 5 are the only primes that end in 2 or 5.
The 772-778 digits of pi are 9999998, the greatest sum of 7 consecutive digits in the first 1,000,000 or so digits.
There are 2,598,960 five-card hands possible in a 52-card deck of cards.
142857 is a cyclic number, the numbers of which always appear in the same order but rotated around when multipled by any number from 1 to 6. 142857 * 2 = 285714 142857 * 3 = 428571 142857 * 4 = 571428 142857 * 5 = 714285 142857 * 6 = 857142
Tycho Brahe, a 16th century astronomer, lost his nose in a duel with one of his students over a mathematical computation. He wore a silver replacement nose for the rest of his life.
If you multiply 1089 x 9 you get the exact reverse, 9801.
What Day of the Week Were You Born On?
Even though you were there at the moment of your birth, you may not remember exactly what day of the week it was. In fact, not only will this method help you find that out, you can find out the day of the week for any date you want in the 1900's. Here is a little trick to help you figure what day that was:
Step 1) Write down the last two digits of the year. Call it A.
Step 2) Divide that number by four dropping the remainder call this answer B.
Step 3) Find the month number corresponding to the month from the table below. Call it C.
Step 4) The day call it D.
Step 5) Take the century number of the year and divide it by four.
If the remainder is 0 then E = 6
If the remainder is 1 then E = 4
If the remainder is 2 then E = 2
If the remainder is 3 then E = 0
Step 6) Now add A+B+C+D+E. Divide this sum by 7. The remainder you get is the key to the day of the week.
Step 7) In the table of days below, match the remainder with the day of week.
| TABLE OF MONTHS | TABLE OF DAYS | LEAP YEARS | ||
| Sunday = 1 | If year divides 400, yes | |||
| Jan = 1 (0 in leap year) | July = 0 | Monday = 2 | If year divides 100, no | |
| Feb = 4 (3 in leap year) | Aug = 3 | Tuesday = 3 | If year divides 4, yes | |
| Mar = 4 | Sept = 6 | Wednesday = 4 | If year does not divide 4, no | |
| April = 0 | Oct = 1 | Thursday = 5 | ||
| May = 2 | Nov = 4 | Friday = 6 | ||
| June = 5 | Dec = 6 | Saturday = 0 | ||
I will read your mind and guess your answer:
* Think of a number between 2 and 9
* Multiply the number by 9
* Add the two digits together
* Subtract 5 from the number you now have
* Convert the number into a letter:1 = a, 2 = b, 3 = c, etc
* Think of a European Country starting with that letter
* Now think of the second letter of that country
* Think of an animal that starts with that letter (This must be an animal - not a bird!)
* What colour is your animal?
Now concentrate carefully on your answers
--------------------------------------------------------
What you are thinking
--------------------------------------------------------
Now try this on all your friends
If you did not get that exact answer,you either thought of a really unique country, a really unique mammal, or you need to re-check your math and try again!
Good Mathematical Card Trick
Here's a real clean card trick that is bound to amaze and surprise your friends or classmates in your MBA programs.
Have a friend shuffle a standard 52-card deck to his satisfaction. The ask him/her to turn over, face up, a pile of twenty-five cards. As they count out the cards to twenty-five, act like you are intensely memorizing every single one of them in order. In truth you are only interested in the 17th card in the pile. Memorize that 17th card..
Turn the twenty-five card pile over, now face down, and set aside.
Take the remaining cards and do the following:
If it is a two through nine card, place it face up, and count out cards up to the number ten. For instance, if you turn up a six, you would place it face up, and then count out four cards coming down, saying "Seven, eight, nine, ten." If you turned up a three, then seven cards, saying "Four, five, six, seven, eight, nine, ten."
If the card you turn up is an ace, ten, or picture, tell your friend that you must have cards 2 through nine for this trick and place the card on the bottom of the deck, face down like the rest of the cards. (Someone told me that aces and pictures work too, but I haven't verified it yet.)
Repeat this procedure until you have completed four columns of "ten counts."
Take whatever remaining cards you have after making the four columns, and place them face down on TOP of the twenty-five card pile you set aside earlier.
Now ask your friend to total up the numbers at the top of the four columns.
Say the total was 23. Counting from the very top of the set-aside-pile-plus-remainder-cards, state you are interested in the 23rd card. Just before turning over the 23rd card, state what card it is!! (Iit is the 17th card that you memorized at the beginning of the trick!)
If you did everything correctly, it works every time! Amazing!
Guess Your Birthday!
Here's a fun trick to show a friend, a group, or an entire class of people. Tell the person (or class) to think of their birthday...and that you are going to guess it.
Step 1) Have them take the month number from their birthday: January = 1, Feb = 2 etc.
Step 2) Multiply that by 5
Step 3) Then add 6
Step 4) Then multiply that total by 4
Step 5) Then add 9
Step 6) Then multiply this total by 5 once again
Step 7) Finally, have them add to that total the day they were born on. If they were born on the 18th, they add 18, etc.
Have them give you the total. In your head, subtract 165, and you will have the month and day they were born on!
How It Works: Let M be the month number and D will be the day number. After the seven steps the expression for their calculation is:
5 (4 (5 M + 6 ) + 9 ) + D = 100 M + D + 165
Thus, if you subtract off the 165, what will remain will be the month in hundreds plus the day!