In math what is the definition of the following. i looked in math book for the definition weren't there.

"of"
"out of"
"multiply fractions"

Of : "The study of numbers, equations, functions, and geometric shapes and their relationships. Some branches of mathematics are characterized by use of strict proofs based on axioms. Some of its major subdivisions are arithmetic, algebra, geometry, and calculus"

Out of: The ratio of a smaller number to a larger, of a part to the whole.

Multiply fractions: "Simplify the fractions if not in lowest terms. Multiply the numerators of the fractions to get the new numerator. Multiply the denominators of the fractions to get the new denominator."