Word Problems to
Algebraic Expressions
Learn to decode everyday language into precise algebraic expressions, turning written clues into symbols you can solve.
What Is an Algebraic Expression?
An algebraic expression is a combination of numbers, variables, and operations that represents a quantity. Unlike an equation, it has no equals sign.
Why Does Translation Matter?
On the SSAT, problems are almost never written as pure math. They are wrapped in words. Your job is to unwrap those words into symbols you can manipulate.
The Vocabulary Map
Every operation has a family of signal words. Memorize these and you can decode almost any sentence on the SSAT.
| Operation | Signal Words | Example |
|---|---|---|
| + Addition | sum, more than, increased by, plus, total | \( x + 7 \) |
| − Subtraction | difference, less than, decreased by, fewer | \( x - 4 \) |
| × Multiplication | product, times, twice, triple, of | \( 3x \) |
| ÷ Division | quotient, divided by, ratio, per, half of | \( \frac{x}{2} \) |
The Core Translation Rule
Order Matters: Subtraction and Division
Addition and multiplication are commutative: \( a + b = b + a \). But subtraction and division are not. The phrase structure tells you which value comes first.
The value after "less than" comes first.
The value after "into" is the numerator.
Expression vs. Equation
The SSAT may ask you to write an expression or an equation. Knowing the difference prevents wrong answer choices.
| Feature | Expression | Equation |
|---|---|---|
| Equals Sign | No | Yes |
| Example | \( 3x + 2 \) | \( 3x + 2 = 14 \) |
| Signal Phrase | "Write an expression for..." | "is", "equals", "the result is" |
| Can You Solve? | Simplify only | Solve for the variable |
How to Translate Step by Step
Example 1: Basic Translation
Example 2: Intermediate Translation
Example 3: Multi-Step Translation
Example 4: Consecutive Integers
The Power of Parentheses
When a word problem says "the quantity", "the sum of ... multiplied by", or "all of ... divided by", it signals that you need parentheses to group operations correctly.
Common Mistakes to Avoid
Quick Reference Table
| English Phrase | Expression | Watch Out |
|---|---|---|
| "6 more than \( x \)" | \( x + 6 \) | Order doesn't matter |
| "6 less than \( x \)" | \( x - 6 \) | Not \( 6 - x \) |
| "the product of 4 and \( x \)" | \( 4x \) | Order doesn't matter |
| "\( x \) divided by 9" | \( \frac{x}{9} \) | Not \( \frac{9}{x} \) |
| "twice the sum of \( x \) and 5" | \( 2(x+5) \) | Not \( 2x + 5 \) |
| "the square of \( x \), decreased by 1" | \( x^2 - 1 \) | Square first, then subtract |
Question 1 of 5
Which expression represents "nine less than twice a number"?
Question 2 of 5
A taxi charges \( d \) dollars per mile plus a $5 flat fee. Which expression gives the cost for \( m \) miles?
Question 3 of 5
Which expression represents "the quotient of the sum of \( x \) and 7, and 3"?
Question 4 of 5
The sum of three consecutive odd integers can be expressed as:
Question 5 of 5
A rectangle's length is 3 more than twice its width \( w \). Which expression represents the perimeter?