Word Problems: Turning English Into Equations
The hardest part of a word problem usually isn't the math — it's the translation. A repeatable system for naming the unknown, converting keywords into symbols, and checking the result turns intimidating paragraphs into routine algebra.
The Short Version
- Word problems test translation as much as math — the system is what makes them reliable.
- Keywords map to operations: "sum" → +, "of" → ×, "is" → =, "less than" → subtract (and flip the order).
- Always define your variable in words first ("let x = the number of adult tickets").
- Check by plugging the answer back into the original sentence — the fastest way to catch a setup error.
Students rarely lose word-problem points because the algebra is hard. They lose them in the translation — misreading "less than," picking the wrong unknown, or skipping the check. The fix is a system. Every word problem, no matter the topic, yields to the same four steps: define the unknown, translate the sentence, solve, and verify. Run that system and the paragraph stops being scary.
This guide gives you the system, a keyword dictionary, the most common problem types, and worked and practice problems matched to real test difficulty at Northside Tutoring.
Why Word Problems Matter
The modern SAT and ACT are overwhelmingly word-based. Pure "solve for x" questions are rare; most problems wrap the math in a real-world story. Translation is therefore the highest-leverage math skill on the test — it determines whether you even set up the right equation.
The Four-Step System
- Define the variable in plain words: "let x = the number of hours worked."
- Translate the sentence phrase by phrase into an equation.
- Solve the equation.
- Check by re-reading the question and plugging the answer back in.
The Keyword Dictionary
| Words | Operation |
|---|---|
| sum, increased by, more than, total | + |
| difference, decreased by, less than, fewer | − |
| product, of, times, twice, each | × |
| quotient, per, divided by, ratio | ÷ |
| is, was, equals, results in, gives | = |
The "less than" reversal
"5 less than x" is x − 5, not 5 − x. The phrase flips the order. The same goes for "subtracted from." This reversal is the single most common translation error.
Defining the Right Variable
Let your variable stand for the quantity the question asks about, and express everything else in terms of it. "Maria is 3 years older than twice Tom's age" becomes M = 2T + 3. Choosing the smaller or simpler quantity as the base usually keeps the algebra cleanest.
Common Problem Types
- Consecutive integers: n, n + 1, n + 2 (or n, n + 2, n + 4 for evens/odds).
- Age problems: write expressions for "now" and "then," watching the time shift.
- Mixture / money: count value, not just quantity (e.g., 5¢ × nickels).
- Distance: distance = rate × time, one equation per traveler.
Checking Your Answer
The check is not optional — it's where you catch translation mistakes. Re-read the original sentence with your answer in place. If "the sum is 30" but your numbers add to 28, the setup was wrong. A ten-second check saves a missed question.
Where You'll See This — Test by Test
Word problems are the dominant format on the modern SAT and ACT, so the translation system pays off on nearly every question. The SSAT uses them heavily too. No reference sheet helps here — method is everything.
Digital SAT
The majority of Math questions are word problems. Translation and defining variables are the core skills the Digital SAT rewards.
Explore SAT Tutoring → College AdmissionsACT
Word problems span every topic. The keyword dictionary and the "less than" reversal show up constantly.
Explore ACT Tutoring → Independent School AdmissionsSSAT
Middle and Upper Levels lean on word problems for arithmetic, fractions, and simple algebra.
Explore SSAT Tutoring → K-12 CurriculumSchool Algebra
A foundational Algebra I skill that underlies modeling in every later math course.
Explore Algebra Tutoring →Watch the Lesson
Sometimes a diagram needs a voice. In the short video below, one of our Northside tutors walks through the core idea and works through test-style problems in real time.
Word Problems — In Plain English
A live walkthrough from our tutoring team.
— Featuring a Northside Tutoring instructor
For the developer / editor
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Worked Example Problems
These problems are calibrated to the difficulty you'll actually see on test day. Try each one before opening the solution.
Five more than twice a number is 17. What is the number?
Show solution
Let x = the number. Translate: 2x + 5 = 17.
2x = 12 → x = 6.
The sum of three consecutive integers is 72. What is the largest?
Show solution
Let the integers be n, n+1, n+2. Sum: 3n + 3 = 72.
3n = 69 → n = 23, so the integers are 23, 24, 25.
A number decreased by 8 equals 15. What is the number?
Show solution
"Decreased by 8" → x − 8 = 15.
x = 23.
Maria is 3 years older than twice Tom's age. Together they are 36. How old is Tom?
Show solution
Let T = Tom's age; Maria = 2T + 3. Total: T + (2T + 3) = 36.
3T + 3 = 36 → 3T = 33 → T = 11.
A piggy bank has only nickels and dimes, 20 coins worth $1.65. How many dimes are there?
Show solution
Let d = dimes, so nickels = 20 − d. Value: 10d + 5(20 − d) = 165 (in cents).
10d + 100 − 5d = 165 → 5d = 65 → d = 13.
Common Mistakes to Avoid
Three traps that catch students every year
- Reversing "less than." "5 less than x" is x − 5. Reading it left-to-right as 5 − x flips the answer's sign.
- Answering the wrong question. The problem may ask for the largest integer or Tom's age, not the variable you solved for. Re-read what's being asked.
- Skipping the check. Plugging back in catches setup errors instantly — the cheapest insurance on the test.
Practice Problems — You Try
Three problems below. Work each before checking the solution.
Seven less than a number is 12. What is the number?
Show solution
x − 7 = 12 → x = 19. (Note the order: not 7 − x.)
Three times a number, increased by 4, is 25. Find the number.
Show solution
3x + 4 = 25 → 3x = 21 → x = 7.
Two trains leave the same station, one at 40 mph and one at 60 mph in opposite directions. After how many hours are they 250 miles apart?
Show solution
Combined separation rate = 40 + 60 = 100 mph. Distance = rate × time: 100t = 250.
t = 2.5 hours.
The Northside Method — How We Teach This 1-on-1
Reading a blog is a great starting point. But there's a meaningful gap between understanding a concept and reflexively applying it under timed conditions. That gap is exactly what our tutors close.
Every Northside student works through a four-step framework:
- Assessment. We diagnose which specific skills are slowing your student down — not just whether they "get it" in the abstract.
- Perfect-match coach. We pair them with an elite tutor (we accept only the top 1% of applicants) whose teaching style fits how your student actually learns.
- Bespoke plan. A roadmap built around your student's target score, target timeline, and current pacing data.
- Data-driven adjustment. Every session ends with a check on whether the student's accuracy and speed are moving in the right direction.
And if a student meets all eligibility requirements but doesn't hit the defined score improvement? We provide 5 additional hours of cohort learning at no cost. That's the Northside guarantee — built on 25 years of measured outcomes.
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