FEMDAS is a mnemonic that helps remember the order of operations in mathematics, standing for Factorials, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right). It emphasizes that calculations involving factorials and exponents should be performed first, followed by multiplication and division, and finally addition and subtraction. This order ensures consistent and correct results when evaluating mathematical expressions. Note that the more commonly used mnemonic is PEMDAS, which stands for Parentheses, Exponents, Multiplication and Division, Addition and Subtraction.