AGR-TEAC61-06 · Lesson 7 · 10 clock hours · demo
Math Word Problems and Problem-Solving Scaffolds
Objective. Students will guide a peer through at least two structured problem-solving frameworks (CUBES strategy and bar model/tape diagram) to solve addition/subtraction and multiplication/division word problems at Grades 3–5 level.
⚠ Pending professional review
This lesson, its worked examples and its practice questions has not yet been verified by a licensed professional in the field or by a certification or approval body. It is a study draft and may contain errors. Do not use it as instructions for work on a job site or on live equipment. Always follow your instructor, your supervising professional, and current official references and regulations.
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Why Math Word Problems Are Hard for Students
Word problems require students to do several things at once: read and understand language, identify what is being asked, choose the right operation, perform the calculation, and check whether the answer makes sense. For many students in Grades 3–5, any one of these steps can break down. As a paraprofessional, your job is not to solve the problem for the student — it is to coach them through a structured process so they build the skill themselves.
Two research-supported tools will guide your work: the CUBES strategy and the bar model (tape diagram).
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The CUBES Strategy
CUBES is an annotation method that slows students down so they read the problem carefully before they touch numbers.
- C – Circle the numbers. Students circle every number in the problem, including numbers written as words ("five apples").
- U – Underline the question. Students underline the sentence that tells them what they must find.
- B – Box key words. Students draw a box around math signal words: total, difference, each, altogether, remaining, times, shared equally, and so on.
- E – Eliminate unnecessary information. Students cross out any detail that is not needed to solve the problem. This step builds critical reading skill.
- S – Solve and check. Students write their work, compute the answer, then re-read the question to confirm they answered what was actually asked.
When you model CUBES as an aide, annotate the problem out loud step by step. When you coach a student, use prompting questions: "What numbers do you see? Can you circle them?" Do not annotate the problem for the student.
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Bar Models and Tape Diagrams
A bar model (also called a tape diagram) is a drawn rectangle divided into sections to represent the parts of a problem visually. Bar models are widely used in Grades 3–5 to connect the language of a word problem to the arithmetic structure.
Part–Whole model (used for addition and subtraction): Draw one long bar divided into two or more labeled sections (the parts). The total goes above or below the whole bar. Students can see whether a part or the whole is missing and choose the correct operation.
Comparison model (used for comparing two quantities): Draw two bars side by side, labeled with each quantity. The difference is shown as the gap. This helps students who confuse "more than" and "less than" language.
Equal-groups model (used for multiplication and division): Draw several equal-sized bars to represent groups. Labeling the number of groups and the size of each group makes the multiplication or division structure visible.
As an aide, ask the student to draw the bar before they write any equation. Prompting questions such as "How many parts does this problem have?" and "Do we know the whole or are we looking for it?" guide the student without giving the answer.
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Prompting, Not Telling
The most important rule for a paraprofessional supporting math is: ask, don't tell. Giving a student the answer — or walking through every step — removes the learning opportunity and creates dependence. Effective prompting questions include:
- "What is the problem asking you to find?"
- "Which numbers matter here?"
- "What operation does the word altogether usually signal?"
- "Does your answer make sense? Is it bigger or smaller than what you started with — and should it be?"
- "Can you draw a bar model to show what's happening in this problem?"
Record which prompts you use on a prompt-language checklist so you and your supervising teacher can track whether the student is becoming more independent over time.
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Analyzing Student Errors
When reviewing student work, label each error in one of three categories:
1. Computational error – The student chose the right operation and set it up correctly but made an arithmetic mistake.
2. Reading/language error – The student misread a number, misunderstood a math vocabulary word, or answered the wrong question.
3. Strategy-selection error – The student chose the wrong operation or set up the problem incorrectly (for example, multiplying when they should have divided).
Once you identify the error type, choose a prompting question that targets exactly that weakness. For a computational error, ask the student to check their arithmetic step by step. For a language error, ask them to re-read and underline the question. For a strategy error, ask them to draw a bar model from scratch.
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Safety and Professional Conduct Notes
Math support sessions take place in classroom or small-group settings. Physical safety hazards are minimal, but two professional-conduct rules always apply:
- Confidentiality: Student work samples and error patterns are educational records. Do not share them outside authorized school channels.
- Scope of role: If a student shows signs of a learning disability or significant processing difficulty not yet identified, document your observations and report them to the supervising teacher. Do not diagnose or label the student yourself.
Always follow your district's policies on one-on-one student contact, including keeping sessions visible to other adults when possible.
Key terms8
CUBES strategyA five-step annotation framework for word problems: Circle numbers, Underline the question, Box key words, Eliminate unnecessary information, Solve and check.
Bar model (tape diagram)A rectangular diagram divided into labeled sections used to represent the mathematical structure of a word problem visually before writing an equation.
Prompting questionA question an aide asks to guide a student's thinking without revealing the answer or completing a step for the student.
Computational errorAn arithmetic mistake made after the student has correctly identified the operation and set up the problem structure.
Reading/language errorA mistake caused by misreading a number, misunderstanding a math vocabulary word, or answering the wrong question.
Strategy-selection errorA mistake in which the student chooses the wrong operation or sets up the problem structure incorrectly.
Part–whole modelA bar model configuration that shows two or more parts making up a total, used to represent addition and subtraction situations.
Signal wordsVocabulary in a word problem that hints at the required operation, such as 'altogether' for addition, 'remaining' for subtraction, or 'each' for multiplication or division.
Worked examples4
1. CUBES annotation example: 'The school store had 48 pencils. Students bought 19 pencils on Monday and 7 pencils on Tuesday. How many pencils are left?'
- C – Circle the numbers: 48, 19, 7.
- U – Underline the question: 'How many pencils are left?'
- B – Box key words: 'left' (signals subtraction).
- E – Eliminate unnecessary information: The days (Monday, Tuesday) are context only; they do not change the math.
- S – Solve: Total pencils sold = 19 + 7 = 26. Pencils left = 48 − 26 = 22. Check: 22 + 26 = 48. ✓
Answer: 22 pencils are left.
2. Bar model example (part–whole): 'Maria picked 35 apples. She gave 14 to her neighbor. How many apples does Maria have now?'
- Draw one long bar labeled 'Total: 35 apples.'
- Divide it into two sections: one labeled '14 (given away)' and one labeled '? (remaining).'
- The whole is known; a part is known; find the other part by subtracting: 35 − 14 = 21.
- Check: 14 + 21 = 35. ✓
Answer: Maria has 21 apples.
3. Bar model example (equal groups): 'A teacher packs 6 boxes of crayons. Each box holds 8 crayons. How many crayons are there in all?'
- Draw 6 equal-sized bars, each labeled '8 crayons.'
- Label the total bar below as '? crayons in all.'
- Recognize the equal-groups structure: 6 groups × 8 each = total.
- Calculate: 6 × 8 = 48. Check by skip-counting: 8, 16, 24, 32, 40, 48. ✓
Answer: There are 48 crayons in all.
4. Error analysis example: A student solved 'Four friends share 36 stickers equally. How many stickers does each friend get?' and wrote '36 − 4 = 32.'
- Identify the error type: The student subtracted instead of dividing — this is a strategy-selection error.
- Check the signal language: 'share equally' is a division signal word.
- Write a corrective prompting question the aide could ask: 'What does it mean to share 36 things equally among 4 people — can you draw a bar model showing 4 equal groups?'
- Correct solution: 36 ÷ 4 = 9. Check: 9 × 4 = 36. ✓
Answer: Each friend gets 9 stickers. (Error type: strategy-selection.)
In class: Instructor models the CUBES strategy (Circle numbers, Underline the question, Box key words, Eliminate unnecessary info, Solve and check) on three word problems displayed on a whiteboard; students annotate copies of the same problems and compare annotations. · In pairs, students take turns playing aide and student while using bar models to set up and solve a multi-step word problem; the 'aide' must use prompting questions only (no solving for the student), recorded on a prompt-language checklist. · Identify errors in four solved student word-problem samples—labeling each error as computational, reading/language, or strategy-selection—and write one corrective prompting question per error that a paraprofessional could ask without giving away the answer.
Materials: Word problem sets (Grades 3–5, mixed operations), CUBES strategy reference card, bar model/tape diagram templates, whiteboard or chart paper, markers, error-analysis student work samples
Check: Role-play observed by instructor: student playing aide uses at least four prompting questions without solving for the partner, confirmed by checklist (pass = 4/5 checklist items met); error-analysis worksheet is graded for correct error categorization with a minimum of 3/4 errors correctly identified and accompanied by an appropriate prompting question.
Practice check8
Answer each question, then check it. Nothing is recorded; this is your own practice.
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