42.) Here is a partial list of different types of numbers: real, imaginary, irrational, complex, transendental, surreal, perfect,
square and triangular.
43.) In a room of 23 people there is a 50% chance that two people have the same birthday.
= sign was invented by Robert Recorde in the 16th. century because he became tired of writing "is equal to". He chose two equal
lines because he felt that no two things were more equal than the two lines =.
45.) A palindrome is a word, sentence or number
that is the same written forwards or backwards. "Noon", "A man, a plan, a canal - Panama", "16461" (palindromic number).
If you drop a needle on a table about 100 times with equally spaced lines drawn on it you can calculate the value of pi using a very
simple formula. This method of finding pi is called Buffon's Needle.
47.) A centillion is 1 followed by 303 zeros except in England
where it is 1 followed by 600 zeros.
48.) "Geometry" is a Greek word meaning earth measure. "Geography" means earth picture.
The only even prime number is 2.