| associative property of addition | For three or more real numbers, the sum is the same regardless of how you group the numbers. For example, (6 + 2) + 1 = 6 + (2 + 1). |
| commutative property of addition | Two real numbers can be added in any order without changing the sum. For example, 6 + 4 = 4 + 6. |
| like terms | Terms that contain the same variables raised to the same powers. For example, 3x and −8x are like terms, as are 8xy2 and 0.5xy2. |
| polynomial | A monomial or the sum or difference of two or more monomials. |