Algebra uses variables ('letters') to represent unknown values or numbers. We can solve problems by translating them into an equivalent mathematical statement, the process by which we call Algebra. We can thank the painstaking work carried out by the Arabian Al Kwarizmi who became instrumental in adapting and spreading the Indian number system of 0 to 9, the numbers we use today. Back in his day, some 1200 years ago, the Roman numeral system was still in use across much of Europe. Al Kwarizmi also wrote many works on Algebra.