Overview
This 60-minute lesson for Year 4, aligned with the National Curriculum for England and White Rose Maths, focuses on solving two-step multiplication word problems with addition, supported by the grid method. The lesson aims to deepen pupils’ conceptual understanding and problem-solving skills using concrete representation and metacognitive questioning.
National Curriculum Links
Mathematics Programmes of Study: Year 4 (Number - Multiplication and Division)
- Use place value, known and derived facts to multiply and divide mentally, including: multiplying by 0 and 1; multiplying together three numbers.
- Multiply two-digit and three-digit numbers by a one-digit number using formal written layout (grid method).
- Solve problems involving multiplying and adding, including using the distributive law to multiply two-digit numbers by one-digit numbers.
- Reasoning and Problem Solving: Solve addition and multiplication two-step problems in contexts, deciding which operations and methods to use and why.
Learning Objectives
By the end of the lesson, pupils will be able to:
- Use the grid method to multiply two-digit numbers by one-digit numbers accurately.
- Solve two-step word problems involving multiplication and addition.
- Explain and justify the choice of methods used to solve word problems.
- Reflect on strategies and identify errors in their reasoning or calculations.
Success Criteria
I can:
- Read and understand two-step word problems involving multiplication and addition.
- Use the grid method to set out and calculate multiplication accurately.
- Identify in which order to use multiplication and addition to solve problems.
- Explain my thinking clearly and justify my answers.
- Check my answers and correct any mistakes.
Resources
- Whiteboards and pens for pupil responses
- Printable or projected word problems
- Grid method multiplication templates
- Example problem and worked solution on the board/visualiser
- Counters or place value charts (optional for modelling)
Lesson Structure
1. Introduction (10 mins) – Engaging Starter and Questioning
Objective: Activate prior knowledge of multiplication and build curiosity about solving multi-step problems.
- Begin with a quick recap of the grid method: present a simple 2-digit by 1-digit multiplication (e.g., 23 × 4).
- Use a visualiser or board to model the grid layout step-by-step while explaining.
- Pose an open-ended question:
- “If Jamie buys 23 packets of pencils, each with 4 pencils inside, how many pencils does he have?” – quick mental check.
- Introduce a two-step word problem involving multiplication and addition. Example:
“Jamie bought 23 packets of pencils (4 pencils in each). Then, he bought 17 more pencils separately. How many pencils does Jamie have in total?”
- Ask pupils to discuss in pairs what steps they would take.
- Targeted questions:
- “Which maths operation should we use first and why?”
- “How will we organise our working out to avoid mistakes?”
- “What does the grid method help us with here?”
AfL Check #1: Use mini whiteboards for pupils to write down the first step’s expression (either multiplication or addition). This allows quick assessment of their understanding of order of operations and problem decomposition.
2. Modelling and Guided Practice (20 mins)
Objective: Model solving two-step multiplication word problems using the grid method; scaffold pupils in applying this independently.
- Display the example problem:
“Jamie bought 23 packets of pencils with 4 pencils in each packet, then 17 single pencils. How many pencils does Jamie have in total?”
- Model setting out the multiplication step using the grid method:
- Partition 23 into 20 and 3, and multiply each by 4.
- Set out the grid with multiplication facts:
| | 20 | 3 |
|---|----|---|
| 4 | 80 | 12|
- Add the two products: 80 + 12 = 92 pencils from packets.
- Explain finding the total by adding the 17 extra pencils:
- 92 + 17 = 109 pencils altogether.
- Emphasise writing clear, organised working out and labelling steps.
- Targeted questions (Bloom’s Taxonomy):
- _“Why did we partition 23 as 20 and 3?” (Understanding)
- _“Could we solve this problem another way? Why or why not?” (Evaluating)
- _“What would happen if we added before multiplying?” (Analysing and Predicting)
- _“How do we know 109 pencils is a reasonable answer?” (Evaluating, Checking)
- Ask selected pupils to explain the reasoning behind each step and justify the method aloud.
AfL Check #2: Observe pupil explanations and responses to questions to assess reasoning skills and identify any emerging misconceptions, e.g., adding before multiplication or errors in grid method layout.
- Hand out similar scaffolded problems for pairs or small groups to solve collaboratively using the grid method and explain their solutions to a partner.
3. Independent Application (20 mins)
Objective: Pupils practise solving a range of two-step multiplication and addition word problems independently or in pairs.
- Provide a worksheet with 3-4 word problems of increasing complexity, each requiring two steps: multiplication using the grid method and then addition.
- Encourage pupils to:
- Read the problem carefully.
- Underline key numbers and operations required.
- Set out the multiplication using the grid method clearly.
- Write the addition step separately and find the final answer.
- Write one or two sentences explaining their approach and checking their answer.
- Teachers circulate to prompt with higher-order questions and provide targeted support:
- “How did you decide which part to multiply first?”
- “Explain why you arranged your grid like this.”
- “Can you check if your answer makes sense?”
AfL Check #3: Use marking, observation, and questioning to check pupil’s method, calculation accuracy, and ability to explain their approach.
4. Plenary (10 mins)
Objective: Consolidate learning, address misconceptions, and encourage reasoning reflection.
- Invite a few pupils to share their solutions and explain their thinking step-by-step, using the grid method and addition clearly.
- Use a “spot the mistake” approach: present an incorrect example on the board where, for instance, addition was done before multiplication or grid method has missing parts.
- Ask the class:
- “Can you find the mistake?”
- “What would you do differently?”
- Summarise the success criteria, reinforcing the importance of using the grid method for multiplication and then adding.
- Finish with a reflective question:
- “Why might solving two-step problems be harder than one-step? How does the grid method help?”
Common Misconceptions and Difficulties
- Mixing order of operations: Pupils may add before multiplying because addition seems simpler. Emphasise the logic of solving multiplication first in multi-step problems.
- Grid method errors: Forgetting to partition numbers correctly, missing cells in grids, or adding part products incorrectly.
- Misunderstanding problem context: Pupils may fail to identify that two steps involve different operations or confuse quantities to be multiplied or added.
- Over-reliance on one method: Difficulty in justifying or explaining other strategies; encourage flexible thinking.
Example for Pupils to Copy
Problem:
A school orders 46 packs of crayons, each containing 5 crayons. Later, they receive an extra 29 crayons as a gift. How many crayons does the school have in total?
Working:
- Multiply 46 × 5 using the grid method:
- Add: 200 + 30 = 230
- Now add the extra crayons: 230 + 29 = 259
- Answer: The school has 259 crayons in total.
This lesson plan enables pupils to build fluency, reason mathematically, and solve multi-step problems confidently, fully aligned with the National Curriculum standards and the White Rose Maths approach.