Solve Word Problems

Overview

In this 30-minute lesson, students use a four-step routine—SEE, CHOOSE, SOLVE, CHECK—to solve real-life addition and subtraction problems. The lesson builds on prior work with place value, addition, subtraction, and interpreting measurement or quantity situations, extending students’ reasoning to problems within 1,000.

Learning intentions

Students will be able to:

• Solve a real-life addition or subtraction problem.
• Identify important information in a word problem.
• Choose an operation and represent it with an equation.
• Check whether an answer makes sense.

Success criteria

• I can circle or select the important numbers and information.
• I can choose addition or subtraction.
• I can solve and write an equation and answer.
• I can check whether my answer makes sense.

Curriculum links

• Measurement and Data — use addition and subtraction to solve word problems involving lengths or quantities given in the same units.
• Measurement and Data — select relevant information and represent a situation with an equation.
• Mathematical practices — make sense of problems, use representations, explain reasoning, and check solutions.
• Grade 2 Georgia mathematics focus — solve addition and subtraction problems within 1,000 using place-value strategies and models.

Lesson structure (30 minutes)

1. 0–4 min · Hook and learning intention. Teacher displays a picture of a classroom supply shelf using the hook and learning intention slides and asks, “There are 125 pencils and 20 more arrive. What might we need to find?” Students turn and talk, then share whether the situation suggests adding, subtracting, or measuring. Teacher introduces: “I can solve a real-life addition or subtraction problem.”

2. 4–10 min · Model SEE, CHOOSE, SOLVE, CHECK. Teacher uses the SEE, CHOOSE, SOLVE, CHECK routine slides to model: “Our class has 125 pencils. The teacher adds 20 pencils. How many pencils are there altogether?” Teacher draws or shows 125 and 20, circles the important numbers, chooses addition, writes 125 + 20 = 145, and checks: “Is 145 more than 125? Does that make sense?” Students identify the information, operation, equation, and check with gestures or brief responses.

3. 10–16 min · Guided problem-solving mat. Teacher distributes number cards, operation cards, and an answer card, then guides the three students in arranging them on the SEE, CHOOSE, SOLVE, CHECK problem-solving mat. Use: “A class has 300 crayons. Students use 75 crayons. How many crayons are left?” Students select 300, 75, and subtraction; place the cards, draw a quick model, solve 300 − 75 = 225, and explain why the answer is reasonable. Prompt with “What information matters?” and “Does ‘left’ suggest addition or subtraction?”

4. 16–24 min · Independent or partner practice. Teacher assigns two picture-supported problems on the two-problem practice page and conferences briefly with each student. Students use the four-step routine for each problem, choosing an operation, writing an equation, solving, and checking. Suggested problems: “A school has 240 red folders and 130 blue folders. How many folders altogether?” and “There are 425 books on a cart. Students take 125 books. How many books are left?” Students may work independently or with a partner, while the teacher records whether each student can identify information, select an operation, calculate, and check.

5. 24–27 min · Share and correct. Teacher displays the discussion and error-analysis slides and asks students to compare solutions for 240 + 130 and 425 − 125. Students explain their operation choice and use a place-value drawing, expanded form, or standard algorithm to justify an answer. Teacher highlights that “altogether” often signals addition and “left” often signals subtraction, while emphasizing that students must understand the story rather than rely on a single clue.

6. 27–30 min · Exit assessment and closure. Teacher gives each student a traffic-light check-in exit ticket and asks students to complete the five quick checks orally or in writing:

• 125 pencils plus 20 pencils means: add, subtract, or measure?
• 300 − 75 = 225, 375, or 275?
• What comes first: understand the story, write the answer only, or hide the numbers?
• To check, ask: “Does my answer make sense?” or another choice?
• 240 + 130 = 270, 370, or 470? Students show a traffic-light self-assessment and explain one answer before leaving.

Resources

• the complete 30-minute problem-solving slide deck
• the SEE, CHOOSE, SOLVE, CHECK problem-solving mat
• Pencils, crayons, or connecting cubes for modeling quantities
• Number cards for 0–1,000
• Addition and subtraction operation cards
• Answer cards
• High-contrast visual step cards for SEE, CHOOSE, SOLVE, CHECK
• Teacher whiteboard or chart paper
• traffic-light check-in exit ticket slips

Assessment

• During modeling and card work, check whether students can identify relevant information, choose an operation, and explain what the answer represents.
• Review the two worksheet problems for an equation, accurate computation, a labeled answer, and a sensible check.
• Use the five-question exit assessment to identify misconceptions about operation choice, subtraction within 1,000, sequence, checking, and addition with hundreds and tens.

Differentiation

• For support, use real classroom objects, smaller numbers, base-ten drawings, large-print number and operation cards, and visual icons for each routine step. Offer a choice between two possible equations.
• Read every problem aloud, pause between sentences, and preteach the vocabulary information, equation, answer, altogether, left, and difference with gestures or simple examples.
• For dyslexia-friendly access, use a clear sans-serif font, large print, high contrast, generous spacing, uncluttered pages, and one problem at a time. Allow students to hear the problem, point to choices, dictate an equation, or give an oral explanation while the teacher scribes.
• For students ready for challenge, ask them to solve a problem in two ways, write a related subtraction or addition equation, or create a new story for 240 + 130.