Multi-Operation
Problems
Master the art of solving multi-step problems that combine addition, subtraction, multiplication, and division: the key to SSAT Quantitative success.
What Are Multi-Operation Problems?
A multi-operation problem requires you to use two or more arithmetic operations: addition, subtraction, multiplication, or division: in a single problem. You must decide which operations to use and in what order to perform them.
Why Does Order Matter?
Consider the expression \( 3 + 4 \times 2 \). If you add first, you get \( 7 \times 2 = 14 \). If you multiply first, you get \( 3 + 8 = 11 \). The correct answer is 11 because multiplication comes before addition.
Where You'll Use This
Multi-operation problems appear everywhere: calculating a shopping total with tax, splitting a restaurant bill, or figuring out how much paint you need for a room. On the SSAT, nearly half of all quantitative questions require more than one operation.
The Order of Operations
Parentheses Change Everything
Parentheses override the default order. Whatever is inside must be solved first, regardless of the operation.
Priority vs. Left-to-Right
Students often confuse two ideas. Priority decides which operation type goes first. Left-to-right decides the order within same-priority operations.
| Priority Rule | Left-to-Right Rule | |
|---|---|---|
| When to use | Different operation types | Same-level operations |
| Example | \( + \) vs. \( \times \): multiply first | \( \times \) then \( \div \): go left to right |
| Common error | Adding before multiplying | Dividing before a multiplication to its left |
Step-by-Step Strategy
Example 1: Basic
Evaluate: \( 12 + 6 \div 3 - 1 \)
Example 2: With Parentheses
Evaluate: \( 5 \times (8 - 3) + 4^2 \)
Example 3: Word Problem
Maria buys 4 notebooks at $3 each and 2 pens at $1.50 each. She pays with a $20 bill. How much change does she get?
Example 4: Nested Parentheses
Evaluate: \( 2 \times [3 + (10 - 4)] \)
Translating Words to Operations
| Word/Phrase | Operation | Example |
|---|---|---|
| sum, total, combined, more than | \( + \) | "5 more than 3" → \( 3 + 5 \) |
| difference, less than, fewer | \( - \) | "8 less than 12" → \( 12 - 8 \) |
| product, times, each, per | \( \times \) | "4 groups of 6" → \( 4 \times 6 \) |
| quotient, divided by, split | \( \div \) | "20 split among 5" → \( 20 \div 5 \) |
Common Mistakes
Summary Checklist
| Step | Action | Mnemonic |
|---|---|---|
| 1 | Solve inside parentheses | P |
| 2 | Evaluate exponents | E |
| 3 | Multiply and divide left to right | M / D |
| 4 | Add and subtract left to right | A / S |
| 5 | Check your answer against the question | ✓ |
Question 1 of 5
What is the value of \( 6 + 2 \times 5 - 3 \)?
Question 2 of 5
Evaluate: \( (9 + 3) \div 4 \times 2 \)
Question 3 of 5
A store sells pencils for $0.75 each and erasers for $0.50 each. Tom buys 6 pencils and 4 erasers. What is the total cost?
Question 4 of 5
What is the value of \( 3^2 + 4 \times (7 - 5) \)?
Question 5 of 5
Evaluate: \( 48 \div (2 + 6) - 1 \times 3 \)