
Mathematical
"U" Words undefined terms A term used without a specific mathematical definition. uniform scale A scale in which numbers that are equally spaced differ by the same amount. When creating a number line or coordinate grid system, you use a uniform scale.
union of two sets The set of elements which are in at least one of the sets.
unit cost The cost per one unit of an object. unit fraction A fraction with 1 in its numerator and a natural number in its denominator.
uniquely determined A situation in which there is exactly one element satisfying given conditions.
unit cube A cube in which every edge has length one unit. unit square A square in which each side has length one unit. unknown A variable which can be assigned different values. unlike terms Terms that involve different variables or the same variable with different exponents.
U.S system of measurement A measurement system in common use in the United States today, based on inches and pounds. Also called the customary system of measurement.

