Addition and subtraction - Add and subtract 1s - Planning

In a Year 3 mathematics lesson on addition and subtraction, the focus is on the concept of adding and subtracting single units from two-digit numbers. The lesson aims to help children recognise the patterns that emerge when performing these calculations. The class starts with a warm-up activity where students count forwards and backwards in ones within the range of 100, stopping at various numbers to reinforce the idea of 'one more' and 'one less'. An engaging game called 'Cowboys' is played to recap this concept, where two students compete to quickly answer questions about number increments. The class then proceeds with partner activities and practical exercises using Base 10 blocks to build numbers and explore the value of digits, particularly when adding or subtracting one from a given number. The children are encouraged to observe what changes occur in the number and what remains the same, especially when not crossing the ten's boundary.

Throughout the lesson, children use stem sentences to articulate their understanding of the relationship between numbers when adding or subtracting one. They are prompted to explore and prove whether adding one to a two-digit number ending in three will consistently result in a number ending in four. The lesson continues with activities designed to further develop fluency in adding and subtracting ones, using part-whole models and counters to visualise and record their findings. Differentiated worksheets are provided for independent work, allowing children to consolidate their learning at varying levels of difficulty. As the lesson concludes, the children reflect on what they have learned, the skills they've used, such as counting on and back, and the strategies that aided their understanding. The lesson plan also addresses common misconceptions and provides scaffolding for students working at different levels, from those just starting to grasp the concept to those ready to delve into greater depth, creating their own number sentence stories and ensuring their calculations remain positive.