Solve One-Step Problems

Overview

In lesson 25 of 30 in Building Mathematical Thinking, students choose an operation to solve one-step word problems. They build on prior work representing addition, subtraction, multiplication, and division situations with objects, drawings, and equations, using individualized number ranges.

Learning intentions

Students will be able to:

• I can identify what is happening in a word problem.
• I can choose addition, subtraction, multiplication, or division.
• I can model and solve a one-step problem.
• I can write an equation and label my answer.

Success criteria

• I can show the quantities with objects, a drawing, or a story mat.
• I can explain why my operation matches the story without relying on keywords.
• I can solve accurately and write an equation with an unknown when needed.
• I can label my answer so it makes sense in the story.

Curriculum links

• Grade 2 Operations and Algebraic Thinking — solve one- and two-step addition and subtraction word problems within 100, representing unknown quantities with drawings and equations.
• Grade 3 Operations and Algebraic Thinking — solve multiplication and division word problems involving equal groups, arrays, and measurement quantities within 100.
• Grade 4 Operations and Algebraic Thinking — represent whole-number word problems with equations and assess whether answers are reasonable.

Lesson structure (30 minutes)

1. 0–4 min · Hook and connect. Display the opening problem in the introduction and hook slides: “There are 3 bags with 4 apples in each bag. How many apples are there?” Ask, “What is happening in this story?” Students silently examine the picture, then explain what quantities and relationships they notice; do not ask them to search for operation keywords.

2. 4–9 min · Model the thinking process. Use the model problem slides to demonstrate the four-part routine: understand the story, choose an operation, model it, and solve and label the answer. Build 3 equal groups of 4 with counters, draw an array, write 3 × 4 = 12, and label “12 apples.” Students help identify the known quantities, select a representation, and check whether the answer fits the story.

3. 9–13 min · Guided operation sort. Present three visual story situations on the guided practice slides: joining, comparing, and equal groups. Read each aloud and invite students to use gestures or a choice card to show addition, subtraction, or multiplication. Students explain their choice to a partner using the frame, “I chose ___ because the story shows ___,” while the teacher checks understanding and corrects choices through the model rather than keywords.

4. 13–23 min · Independent or supported practice. Distribute the one-step problem-solving worksheet. Students solve four differentiated problems, using counters, drawings, number lines, arrays, or equations. The teacher works with a small group or individual students using story mats: read one problem aloud, highlight the quantities, act out the situation, and ask, “What is changing or being compared?” Students complete the model, equation, solution, and label for each problem.

5. 23–27 min · Strategy share and check. Return to the discussion and strategy slides and display one practice problem. Invite two students to show different representations, such as a drawing and an equation or counters and a number line. Students compare the strategies and use a verbal response, pointing, or the sentence frame “Both strategies show ___, so the answer is ___.”

6. 27–30 min · Exit check and close. Display the final problem in the exit prompt slide: “A teacher has 18 stickers and shares them equally among 3 students. How many stickers does each student get?” Students show or describe a model, choose division, solve, and label “6 stickers each.” Collect responses and ask students to self-assess by showing one finger for “I need help,” two for “I can do this with a model,” or three for “I can explain my choice.”

Resources

• the one-step problem-solving slide deck
• the one-step problem-solving worksheet
• Counters, linking cubes, or small classroom objects
• Ten-frames, number lines, and array grids
• Story mats with spaces for quantities, action, model, equation, and answer
• Pencils, crayons, and highlighters
• Optional headphones or text-to-speech device

Assessment

• During the hook and guided sort, listen for whether students identify the relationship in the story and choose an operation based on the situation rather than a memorized keyword.
• During practice, check each student’s model, equation, computation, and label. Record whether support was needed to understand the story, select the operation, model, or calculate.
• Use the final problem as an exit ticket. A successful response includes an appropriate operation, a representation, a correct answer, and a meaningful label.

Differentiation

• Support: Use smaller numbers within 10, then within 20; provide counters, story mats, picture supports, pre-drawn models, and two operation choices. Work one-to-one or with a small group and repeat the same four-part routine.
• Grade-level access: Use addition and subtraction within 100 and multiplication or division within 100, depending on readiness. Allow students to draw, build, act out, or verbally explain before recording an equation.
• Dyslexia-friendly options: Read every problem aloud or provide text-to-speech. Highlight only the quantities and question, use uncluttered text and clear spacing, provide picture-supported problems, and accept verbal answers recorded by an adult or device.
• Advanced learners: Solve a problem using two different strategies, explain why both work, and write a related one-step problem with a matching equation. Invite them to include an unknown in a different position, such as ? × 4 = 20.

Extension

• Students create a picture story for a chosen operation, swap with a partner, and solve one another’s problems.
• Students change one quantity in a solved problem and explain how the answer changes.