Adding and Subtracting

Overview

This 30-minute lesson aims to reinforce Year 2 pupils’ understanding of adding and subtracting numbers within 100, aligned with the National Curriculum for England: Mathematics - Number - Addition and Subtraction objectives.

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National Curriculum Reference

Year 2 Programme of Study - Number - Addition and Subtraction:

• Use addition and subtraction facts to 20 confidently and derive related facts up to 100.
• Add and subtract numbers using concrete objects, pictorial representations, and mentally, including: a two-digit number and ones; a two-digit number and tens; two two-digit numbers.
• Recognise and use the inverse relationship between addition and subtraction and use this to check calculations and solve missing number problems.

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Learning Objectives

By the end of the lesson, the pupil will:

• Confidently add and subtract two-digit numbers and ones/tens using a variety of methods (concrete and pictorial).
• Demonstrate understanding of the inverse relationship between addition and subtraction to check answers.
• Solve simple missing number problems involving addition and subtraction.

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Resources

• Number cards (0-100)
• Place value counters (tens and ones)
• Whiteboard and pens
• Mini whiteboard and pen for pupil
• Visual addition/subtraction number lines
• Printable “missing number” problem sheets (age-appropriate)

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Lesson Structure

1. Introduction (5 minutes)

• Begin with a quick mental warm-up: recap addition and subtraction facts to 20 (e.g., 8 + 7, 15 - 9). Use vibrant flashcards or an interactive whiteboard.
• State lesson objectives and explain the importance of using both concrete objects and mental methods.

2. Teaching and Modelling (8 minutes)

• Introduce adding/subtracting a two-digit number and ones using place value counters. Demonstrate with 34 + 5: group 3 tens counters and 4 ones counters, add 5 more ones, regroup if necessary.
• Model subtraction similarly (e.g., 46 - 7). Use pictorial number lines to show jumps when subtracting ones and tens.
• Emphasise the inverse relationship: Show 46 - 7 = ? and then 39 + 7 = 46 to check.
• Write examples on the whiteboard; involve the pupil by asking how to work out the problems and check answers.

3. Guided Practice (10 minutes)

• Present 5 mixed problems (e.g., 27 + 6, 52 - 20, 45 + 12, 63 - 7, missing number 40 - ? = 25).
• For each problem:
  • Let the pupil use place value counters first.
  • Then draw pictorial aids or number lines.
  • Encourage the use of mental methods for simpler calculations.
  • Prompt the pupil to check answers using the inverse operation.
• Provide immediate, specific feedback and praise accurate use of concepts.

4. Independent Application (5 minutes)

• Give the pupil a few missing number problems to solve on their mini whiteboard (e.g., ? + 8 = 45, 56 - ? = 29).
• Ask them to explain their strategies aloud, reinforcing understanding of inverse operations.
• Circulate to support and scaffold where needed.

5. Plenary and Assessment (2 minutes)

• recap: Ask the pupil to explain how they add and subtract numbers and how they check their answers.
• Use a quick “true or false” quiz on the inverse relationship (e.g., If 38 + 14 = 52, then 52 - 14 = 38, true or false?).
• Make note of any misconceptions or areas needing reinforcement.

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Assessment for Learning

• Observation during guided and independent practice focusing on the use of concrete and pictorial methods.
• Marking responses to missing number problems for accuracy and strategy.
• Verbal explanations assessing conceptual understanding of inverse operations.

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Differentiation

• Support: Use more concrete resources and pictorial aids. Simplify numbers (within 50). Model every step carefully.
• Challenge: Extend to adding and subtracting two two-digit numbers mentally where appropriate. Include word problems requiring addition or subtraction reasoning.

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Cross-curricular Links

• English: Encourage explanations in full sentences to build mathematical vocabulary.
• ICT: Use a simple educational maths app for additional interactive practice outside lesson time.

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Reflection and Next Steps

• Record success in pupil’s use of inverse operations and confidence with two-digit number calculations.
• Plan next lesson on applying addition and subtraction in real-life contexts, e.g., money or measurement problems.

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This detailed, engaging plan ensures a solid grasp of addition and subtraction skills within the Year 2 curriculum, using hands-on and mental methods to deepen conceptual understanding while fostering self-checking and confidence.