Addition and Subtraction - Subtract a three digit number from a three digit number (exchange) - Planning

In the Year 4 curriculum focusing on Autumn Addition and Subtraction, Lesson 7 introduces pupils to the concept of subtracting a three-digit number from another three-digit number with the need for exchange. This step in their mathematical development is facilitated through a variety of resources including place value mats, counters, worksheets, and a presentation. Key vocabulary such as 'place value', 'digit', 'exchange', and 'subtraction' is emphasised to ensure students are familiar with the terminology. The lesson begins with a recap of previous learning and a practical activity where children use concrete manipulatives to understand the necessity of exchanging tens for ones when the numbers in a column do not allow for direct subtraction. Students are encouraged to link this practical understanding to the abstract column method and to record their exchanges accurately.

Further activities involve group work and partner discussions to build fluency in the subtraction method, with a focus on explaining the process using digital apps if available. The lesson also addresses common misconceptions such as the use of zero as a placeholder and the non-commutative nature of subtraction. Independent work is supported by differentiated worksheets that cater to varying levels of understanding, from 'working towards' to 'greater depth'. Reflection is encouraged at the end of the lesson, with pupils identifying what they've learned about subtraction, the skills they've used, and any challenges they've faced. The lesson aims to ensure that all children understand when and why we exchange in subtraction and can confidently apply this knowledge to their calculations.