Interestingly, the number 18 holds a special significance for many cultures and religions.

In the Bible, it is the number of years missing from the life of Jesus Christ. In China, the number is associated with prosperity, the 18th floor of many buildings is the most expensive, and during the Tang dynasty scholarly groups numbering 18 members were considered particularly auspicious. In Japan, the number 18 is derived from the Buddhist concept of 6 x 3, where six represents color, voice, taste, smell, touch, and justice, and three represents good, bad, and peace. Daisuke Matsuzaka, the Japanese baseball superstar now playing for the Boston Red Sox, never parts with his number 18 jersey.

The Bhagavad Gita (Song of God), regarded as a sacred text in Hindu traditions, is comprised of 18 chapters. Eighteen is considered as the code number to break into the soul of the Nature. The significance of 18 can be traced back to the Vedic age. The first Veda, believed to be protected by Lord Brahma himself, had 18 chapters. Later, Veda Vyasa divided it to create the four vedas: Rigveda, Yajur Veda, Sama Veda and Atharava Veda. Each of these vedas had 18 chapters. Veda Vyasa also wrote 18 puranas and 18 upa-puranas.

In the Jewish tradition, it is the number signifying Life. The word for "life" in Hebrew is "chai." The two Hebrew letters that make up the word "chai" are chet and yud. In Gematria (the numerical value of Hebrew letters), chai is equivalent to 8 and yud is equivalent to 10. So "chai", chet and yud together, equals 18. Giving money in multiples of 18 is symbolic of giving "chai" or life. Many people give money in multiples of 18 as presents to someone celebrating a birth, a bar or bat mitzvah or a wedding