Why We Donate in Multiples of $18

Each Hebrew letter has a numerical equivalent, and the sum of the letters that create the Hebrew word for life, CHAI, is 18, chet  (numerical value of 8) plus yud (numerical value of 10). As a result of its connection to the word for life, the number 18 is considered a special number in Jewish tradition. For this reason, Jews frequently make gifts or charitable contributions in multiples of $18.