Order of Operations

Definition

The order of operations is a set of rules that dictates the sequence in which mathematical operations should be performed to accurately evaluate expressions. These rules ensure consistency in calculations and are essential when working with expressions that involve multiple operations such as addition, subtraction, multiplication, and division. The standard acronym used to remember this sequence is PEMDAS, which stands for Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right).

5 Must Know Facts For Your Next Test

1. The order of operations is crucial for obtaining the correct answer in calculations involving multiple operations.
2. When using PEMDAS, operations inside parentheses should always be performed first before addressing exponents.
3. If an expression contains both multiplication and division or addition and subtraction, these operations should be performed from left to right.
4. Misapplying the order of operations can lead to incorrect results, making it essential for students to master these rules.
5. The order of operations applies not only to basic arithmetic but also extends to algebraic expressions involving variables.

Review Questions

• Explain why the order of operations is important when evaluating mathematical expressions.
  • The order of operations is vital because it provides a standardized method for evaluating mathematical expressions. Without these rules, different people might interpret and solve an expression differently, leading to inconsistent results. By following the order defined by PEMDAS, everyone can arrive at the same answer for any given expression, ensuring clarity and accuracy in mathematics.
• How would you evaluate the expression 3 + 4 × 2 using the order of operations? Show your steps.
  • To evaluate 3 + 4 × 2 using the order of operations, we first identify the multiplication operation. According to PEMDAS, we perform multiplication before addition. So we calculate 4 × 2 first, which equals 8. Then we add this result to 3: 3 + 8 = 11. Therefore, the final answer is 11.
• Create a complex expression that requires multiple applications of the order of operations and explain how you would solve it step-by-step.
  • Consider the expression (2 + 3) × (5 - 1)² ÷ 4. To solve it step-by-step using the order of operations, we start with the parentheses: (2 + 3) = 5 and (5 - 1) = 4. Next, we evaluate the exponent: 4² = 16. Now our expression looks like 5 × 16 ÷ 4. Following PEMDAS, we perform multiplication first: 5 × 16 = 80. Finally, we divide by 4: 80 ÷ 4 = 20. Thus, the solution to the expression is 20.

Related terms

PEMDAS:

An acronym representing the order of operations: Parentheses, Exponents, Multiplication and Division (left to right), Addition and Subtraction (left to right).

Expression: A combination of numbers, variables, and operators that represents a value but does not contain an equality sign.

Equation: A mathematical statement that asserts the equality of two expressions, typically containing an equal sign.