With decimal numbers there are "only" 10 possible values a single digit can be; 0 through 9, and to get numbers larger than 9 we just start adding more digits to the front.

Warnings Excel will only produce binary numbers with up to 10 bits. This means that it can only convert decimal numbers greater than -513 and less than 512.

Computer scientists have borrowed from the world of geology and crystals to help machines better generate random numbers. Here's how their method works.