L10 3-Digit Column Subtraction, with exchanges

This Year 3 subtraction resource focuses on teaching children how to subtract 3-digit numbers using the formal written method with exchanges . The lesson begins with a recap of prior learning from Year 3 place value and the Year 2 summer term. Children revisit the column subtraction method learned in the previous lesson by discussing key questions such as: What does each column represent? Which column do we start with? Why is it important to line up the digits? A shared worked example prepares pupils for the new learning and reinforces accuracy and place value understanding. In the introduction, the teacher explains that the lesson will focus on column subtraction where an exchange (regrouping) is required. Base-10 resources are used to model the process, showing how to subtract when the ones cannot be taken away directly. The slides demonstrate how to exchange one ten for ten ones and how to record the exchange clearly. Children then follow a guided example on their whiteboards and complete a second example with a partner, providing an opportunity to check understanding before independent work begins. During the main activity, children apply the column method with exchanges to solve a variety of subtraction calculations. Using the cut-up resource sheet, pupils select questions one at a time and record each calculation in their maths books, drawing the column layout themselves. Some children may benefit from using place value counters or base-10 equipment to support their understanding of subtraction with regrouping and ensure correct digit alignment. The plenary consolidates the key steps needed when exchanging during subtraction. The teacher asks, “What do we need to remember to do when we make an exchange?” Children share completed work and discuss common errors through an example of Zach’s calculation, where he has not completed the exchange correctly. The slides model the correct method, helping pupils understand the importance of recording exchanges and aligni