Systems Word Problems and Modeling
I can write a system from a context, name what the letters mean, and solve it.
What students learn
Students learn to define both variables with units, write one equation per fact, solve, and answer in words with units.
See inside
The key rule
Write one equation per fact, dollars equal to dollars; solve, answer in words, then check in the story.
count = count; $ = $
Read each side aloud with its unit: tickets = tickets, dollars = dollars.
Watch out
9 items cost $66: shirts (x) $9 each, hats (y) $6 each. A student writes the dollar fact.
The mistake: 9x + 6y = 9Dollars on the left, items on the right.
The fix: 9x + 6y = 66Dollars on both sides: $66.
The mistakes it targets
- Writes an equation with different units on its two sides
- Reports the right numbers against the wrong labels
- Uses x + y for a perimeter instead of 2x + 2y
- Stops after finding one value
The interactive Teacher Deck (33 slides, PowerPoint)
- The Learn page taught on screen: 8 fill-in blanks, each filled on its own click as students write it
- The worked example one slide per step (five steps), each with the reason for the step
- Six practice and three apply problems: a your-turn slide with a think-time bar, then the solution one line per click
- Jump buttons on every slide: go straight to any problem, the answer bank or the exit ticket
- Speaker notes on each problem: the question to ask, the worked answer and the common error to listen for
- A completed deck PDF (19 pages) with every slide fully built, to print or post
The student packet (9 pages)
- Learn: guided notes with four definitions, the key rule, a worked example and a Watch Out error pair
- Practice: two warm-up, two standard and two stretch problems, with an answer bank for self-checking that hides three common-mistake decoys
- Apply: one word problem, a reasoning prompt and one error analysis
- Assess: an exit ticket of four items, two per page, with an I-can self-rating
- Homework (page 5): eight new problems, two warm-up, four standard and two stretch
- Answer key (pages 6–7): every problem worked step by step, four common mistakes with what to do about each, and a grading guide, plus the homework key (page 8)
- Color and ink-saver editions of the whole packet
Standard codes refer to the Common Core State Standards for Mathematics. Math Class 678 is an independent publisher, not affiliated with, sponsored by, or endorsed by NGA Center or CCSSO. Every product is sold on Teachers Pay Teachers.