By the age of 13, Louis had developed his own codes, which he thought were even better than Barbier’s. By October 1824, when Louis was only 15 years old, he had improved his system so that it worked effectively. His method used a combination of raised dots that represented actual letters of the alphabet instead of sounds. Using Braille’s method, blind people could learn to spell and read the same alphabet as sighted people. Braille's code used fewer dots, making it easier to learn, and in a pattern small enough to fit under a single fingertip, making the dots faster to read. Each grouping of 6 dots, called a cell, is 3 dots high and 2 dots wide and allows for 64 different characters, including letters, numbers, spaces, punctuation and accent marks, and, later, mathematical symbols and musical notation.