divisor	The number that you are dividing by in a division problem. In the problem , 2 is the divisor.
factor	A number or mathematical symbol that is multiplied by another number or mathematical symbol to form a product. For example, in the equation 4 • 5 = 20, 4 and 5 are factors.
identity property of 1	When you multiply any number by 1, the product is the same as the original number. For example, 9(1) = 9.
inverse operations	A mathematical operation that can reverse or “undo” another operation. Addition and subtraction are inverse operations. Multiplication and division are inverse operations.
multiplicative inverse	Two numbers are multiplicative inverses if their product is 1. For example, .
quotient	The result of a division problem. In the problem , 4 is the quotient.
real numbers	All rational or irrational numbers.
reciprocal	A number that when multiplied by a given number gives a product of 1. For example, and are reciprocals of each other.