Writing expressions
Translate word phrases into algebraic expressions.
Objective
Translate word phrases into algebraic expressions.
What it means
An algebraic expression uses numbers, variables, and operations to represent a word phrase without an equals sign.
Key terms
- Expression
- A math phrase combining numbers, variables, and operations.
- Sum, difference, product, quotient
- Words that signal add, subtract, multiply, divide.
Rules to remember
- 'More than' and 'sum' signal addition.
- 'Less than' reverses order: '5 less than x' means x - 5.
- 'Times' and 'product' signal multiplication.
Step by step
- 1Find the operation wordLook for key words like sum, difference, product, or quotient.
- 2Assign the variableLet the unknown quantity be a letter.
- 3Write the expressionOrder terms correctly, watching for 'less than' reversals.
Common mistakes
- Writing '5 less than x' as 5 - x instead of x - 5.
- Forgetting parentheses around a sum before multiplying.
Tips
- Read the phrase right to left when you see 'less than'.
- Underline the operation keyword first.