Bar and bat mitzvah mean, literally, son and daughter of the commandment.. Bat mitzvah is Hebrew, while bar mitzvah, historically a much earlier ceremony, is Aramaic. The word bar is the Aramaic equivalent of the Hebrew ben (son of) .
In math, the mean is the average of a set of numbers. To determine the mean, add all numbers in a set and take this answer and divide it by how many numbers are in the set. Continue Reading.
Math uses formal proof and definitions, which is entirely different. No, math is not a science. Math is actually more a language than anything else: a completely formalized quantitative language with rigorous dynamics. Science is a method more than anything else, and it is a method not used in mathematics.