# vs.eyeandcontacts.com

## Facts on Mathematics

1. Zero is the only number which can not be represented by Roman numerals.

2. Do you known what comes after a million, billion and trillion? It's a quadrillion, quintillion, sextillion, septillion, octillion, nonillion, decillion and undecillion.

3. Plus (+) and Minus (-) sign symbols were used as early as 1489 A.D.

4. 2 and 5 are the only primes that end in 2 or 5.

5. Do you know that an icosagon is a shape with 20 sides.

6. Among all shapes with the same perimeter, a circle has the largest area.

7. Among all shapes with the same area, circle has the shortest perimeter

8. 40 when written "forty" is the only number with letters in alphabetical order, while "one" is the only one with letters in reverse order.

9. 'Four' is the only number in the English language that is spelt with the same number of letters as the number itself

10. From 0 to 1,000, the letter "A" only appears in 1,000 ("one thousand").

11. 12,345,678,987,654,321 is the product of 111,111,111 × 111,111,111.

12. This is very interesting fact that the opposite sides a die always add up to 7.

13. Trigonometry is the study of the relationship between the angles of triangles and their sides.

14. Abacus is considered the origin of the calculator.

15. To check divisibility of any number by number 3. A number is divisible by three if the sum of its digits is divisible by three (3)

16. Do you know the magic of no. nine (9)? Multiply any number with nine (9) and then sum all individual digits of the result (product) to make it single digit, the sum of all these individual digits would always be nine (9).

17. If you add up the numbers 1-100 consecutively (1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + ... + 100) the sum results 5050.

18. A 'jiffy' is an actual unit of time for 1/100th of a second

19. Do you know what is a Palindrome number? It is a number that reads the same backwards and forward, e.g. 12421

20. If you add 2 even numbers the result you get is same e.g. 2 + 6 = 8, 10 + 4 = 14