Subtracting 3-Digit Numbers

Overview

Duration: 60 minutes
Class: Year 3 (ages 7-8)
Class Size: 30 students
Curriculum Reference:

• Mathematics Programme of Study (Number - Addition and Subtraction)
• National Curriculum for England (Key Stage 2, Year 3)
• Pupils should be taught to “add and subtract numbers mentally, including: a three-digit number and ones, a three-digit number and tens, a three-digit number and hundreds” and to “solve problems, including missing number problems, using number facts, place value, and more complex addition and subtraction.”

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Learning Objectives (WALT)

WALT:

• Understand and solve subtraction word problems involving 3-digit numbers
• Use place value and column subtraction methods to find accurate answers
• Explain their reasoning clearly when solving problems

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Success Criteria

• I can read and understand subtraction word problems involving 3-digit numbers.
• I can subtract 3-digit numbers correctly using written methods.
• I can use place value knowledge to solve word problems step-by-step.
• I can check my answers by estimating or using inverse addition.

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Resources

• Whiteboard and markers
• Place value charts
• Base-10 equipment (hundreds, tens, ones)
• Subtraction word problem task sheets (differentiated)
• Self and peer assessment checklists
• Interactive game (digital or card-based) for warm-up

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Lesson Structure

1. Warm-Up Game (10 minutes)

WALT: Recall place value knowledge and subtraction facts

• Play a subtraction “Fact Attack” game: In pairs, students draw cards with 2- or 3-digit numbers. One student reads out a number ("345"), the other subtracts a single digit or tens mentally (e.g., 345 - 40).
• Use mini whiteboards for quick responses and points awarded for accuracy and speed.
• Reinforces fluency with numbers and subtraction facts leading into today's focus.

Differentiation:

• Support learners use physical counters or place value charts during the game.
• Advanced learners try subtracting 3-digit and 2-digit numbers mentally.

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2. Teacher Input & Modelling (15 minutes)

WALT: Understand how to solve subtraction word problems using column subtraction

• Introduce a simple 3-digit subtraction word problem, e.g., “Lucy has 534 marbles. She gave 128 marbles to her friend. How many marbles does Lucy have left?”
• Model reading the problem aloud and underlining important numbers and key words (e.g., “gave”).
• Demonstrate using column subtraction with regrouping/bonding on the whiteboard.
• Emphasise place value: subtract hundreds from hundreds, tens from tens, and ones from ones.
• Show how to check answers using inverse addition.

Success criteria reminder:

• Can identify 3-digit numbers and smaller numbers in problems.
• Can set out column subtraction correctly.
• Can explain their steps clearly.

Differentiation:

• Provide sentence starters and problem-solving frames for learners who need language support.
• Visual aids and place value columns for learners struggling with regrouping.
• Challenge advanced learners with problems involving subtraction across zeroes (e.g., subtracting 208 from 500).

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3. Guided Practice (15 minutes)

WALT: Apply column subtraction to solve word problems with support

• Hand out differentiated worksheets:

  • Support group: Word problems with numbers that do not require regrouping or borrowing; use of base-10 blocks can be encouraged.
  • Main group: Word problems requiring regrouping, presented step-by-step.
  • Advanced group: Multi-step word problems involving subtraction of 3-digit numbers, sometimes with missing numbers in the problems.

• Circulate, supporting learners, asking questions like:

  • "What is the question asking?"
  • "Which numbers will you subtract first?"
  • "How do you know you need to regroup here?"

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4. Independent Work (15 minutes)

WALT: Solve 3-digit subtraction word problems on my own

• Students complete a short set of 4-5 word problems on individual whiteboards or worksheet.
• Encourage students to apply all strategies learned and check their answers by inverse addition.
• Collect work or use peer-assessment with question prompts.

Extension activity for advanced learners:

• Create their own subtraction word problems with 3-digit numbers and swap with a partner to solve.
• Solve problems with missing digits or unknowns (e.g., 8?5 - 237 = 368).

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5. Plenary & Reflection (5 minutes)

WALT: Reflect on what I have learned about subtraction word problems

• Use a quick “exit ticket” where students write one thing they found easy and one thing they found challenging.
• Revisit key points about place value and column subtraction.
• Ask pairs to share their strategies for solving the problems.

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Assessment Opportunities

• Observation during guided and independent practice
• Review of subtraction workbooks and exit tickets
• Oral questioning and use of mini-whiteboards during warm-up and plenary
• Use of success criteria checklist for self and peer assessment

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Differentiation Summary

Learner Type	Strategies	Resources/Support
Struggling learners	Use of visual aids, base-10 manipulatives, step-by-step problem frames	Place value charts, sentence starters
EAL learners	Clear vocabulary explanations, paired work for language support	Word banks, sentence starters
Advanced learners	More complex word problems, missing number problems, creation of own problems	Challenge worksheets, problem cards

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WOW Factor Ideas

• Use a short video animation showing subtraction as “taking away” objects from a 3D scene.
• Incorporate a digital interactive subtraction game on the whiteboard to vary delivery.
• Introduce a “Subtraction Detective” theme, where pupils solve “mysteries” by decoding subtraction word problems.
• Provide personalised subtraction passports where students tick off new skills learned each lesson.

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By carefully blending hands-on activities, modelling, differentiation, and creative extensions, this lesson plan will engage Year 3 students while meeting all expectations of the National Curriculum for England.