Evaluating expressions

Objective

Evaluate algebraic expressions by substituting values and using order of operations.

What it means

Evaluating an expression means replacing each variable with its given value and simplifying using order of operations.

See it

Use this model while you read. Move it around to see what the math is doing.

Key terms

Evaluate

To find the numerical value of an expression.

Order of operations

Parentheses, exponents, multiplication/division, addition/subtraction.

Rules to remember

• Substitute every variable with its given value before computing.
• Follow order of operations: parentheses, exponents, multiply/divide, add/subtract.
• Use parentheses around negative substitutions to avoid sign errors.

Step by step

1. 1SubstituteReplace each variable with its value, using parentheses.
2. 2SimplifyApply order of operations to compute the final value.