Mathematics · Primary 3

Active learning ideas

Solving 2-Step Word Problems (Addition and Subtraction)

Active learning works for this topic because students need to slow down and analyze problems before computing. When they construct bar models, debate operation orders, and simulate real purchases, they practice the careful reading and planning that prevents rushed errors in multi-step problems.

• MOE Syllabus Outcomes
• MOE: Numbers and Algebra - P3
• MOE: Whole Numbers - P3

• 25–40 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Numbered Heads Together
• 35 min · Pairs

Pairs: Bar Model Construction

Provide word problems printed on cards. In pairs, students draw bar models step-by-step on mini-whiteboards, labeling the first operation and final total. Pairs swap boards with another duo to check and solve. Conclude with a class share-out of strategies.

How do you decide which operation to perform first in a two-step problem?

Facilitation Tip

During Bar Model Construction, ask each pair to justify their first step aloud before drawing the model, forcing them to verbalize the 'find first' clue they spotted.

What to look for

Provide students with the following problem: 'Sarah had $50. She bought a book for $15 and a toy for $22. How much money does Sarah have left?' Ask students to write down the two steps they would take to solve the problem and the final answer.

• Remember
• Understand
• Apply
• Relationship Skills
• Self-Management

Activity 02

• Numbered Heads Together
• 40 min · Small Groups

Small Groups: Operation Sequence Relay

Divide a two-step problem among group members: one finds the first-step answer, passes to the next for the second step, then the last checks with a bar model. Groups race against time but prioritize accuracy. Debrief misconceptions as a class.

What information do you need to find before you can answer the final question?

Facilitation Tip

In Operation Sequence Relay, assign roles so students must agree on the next operation before touching the next problem card.

What to look for

Present students with a word problem on the board. Ask them to draw a bar model to represent the problem. Then, have them write the two number sentences needed to solve it, indicating which operation comes first.

• Remember
• Understand
• Apply
• Relationship Skills
• Self-Management

Activity 03

• Numbered Heads Together
• 30 min · Whole Class

Whole Class: Real-Life Problem Simulations

Pose a shopping or event-planning scenario. Students stand and mimic actions with counters or drawings: add items first, subtract costs second. Vote on sequences via hand signals, then model correct bar on the board together.

How can a bar model help you plan the steps to solve a problem?

Facilitation Tip

During Real-Life Problem Simulations, limit props to exact dollar amounts so students practice precise subtraction and addition rather than estimation.

What to look for

Pose this question: 'When solving a two-step word problem, how do you know if you should add or subtract first?' Facilitate a class discussion where students share their strategies, referring to examples and using vocabulary like 'total' and 'left'.

• Remember
• Understand
• Apply
• Relationship Skills
• Self-Management

Activity 04

• Numbered Heads Together
• 25 min · Individual

Individual: Problem Puzzle Sort

Give students cut-out strips with problem parts, operations, and numbers. They sequence them correctly and glue into bar model templates. Peer review follows, with pairs explaining choices.

How do you decide which operation to perform first in a two-step problem?

What to look for

Provide students with the following problem: 'Sarah had $50. She bought a book for $15 and a toy for $22. How much money does Sarah have left?' Ask students to write down the two steps they would take to solve the problem and the final answer.

• Remember
• Understand
• Apply
• Relationship Skills
• Self-Management

A few notes on teaching this unit

Teach this topic by modeling aloud how you read a problem twice, circle key phrases, and ask yourself if you need a total or a remainder first. Avoid rushing into computation; insist on bar models that label unknowns before any numbers appear. Research shows students benefit from seeing the teacher struggle through a wrong first step and then correct it, so plan to deliberately make and fix a few errors together.

Students should confidently identify the first step, explain why it comes first, and show how each operation connects to the next. Bar models become tools they use independently, not just temporary sketches, and they can articulate how units and final questions guide their choices.

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Watch Out for These Misconceptions

• During Bar Model Construction, watch for pairs who draw models but cannot explain why addition or subtraction comes first.

  Pause the class and ask each pair to share their model with another pair, forcing them to justify the sequence using the problem's wording before moving on.

• During Operation Sequence Relay, watch for students who switch operations without checking if the first step answer makes sense.

  Have the team re-read the final question aloud after each step to verify that their partial answer still points toward the right total.

• During Problem Puzzle Sort, watch for students who solve all steps correctly but answer the wrong question.

  Ask them to highlight the final question in each problem card before starting, then compare their answer to that highlighted phrase before turning in their work.

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Methods used in this brief

• Numbered Heads Together