Addition and subtraction - Add and subtract two-digit and ​three-digit numbers not crossing 10 or 100​ - Presentation

In this engaging mathematics presentation, Year 6 students are introduced to the concepts of adding and subtracting two-digit and three-digit numbers without crossing the boundaries of 10 or 100. The lesson starts with a discussion on the importance of correctly aligning numbers on a place value chart and understanding the value of each digit within the columns. Students are then prompted to recall this fundamental concept, which is essential for accurate calculations. The presentation includes a variety of activities designed to strengthen students' fluency and reasoning skills. In the first activity, learners are tasked with matching calculations to their correct representations on a place value grid, reinforcing their understanding of hundreds, tens, and ones.

The second activity encourages students to represent calculations using base 10 materials, providing a visual and tactile approach to learning. This activity not only helps students to visualise the numbers they are working with but also prompts them to consider the differences between the processes of addition and subtraction. Further slides in the presentation offer reasoning challenges, such as identifying errors in place value alignment or understanding the commutative property of addition through real-life scenarios involving sweets and nuts. Students are also given independent work tasks that include using base 10 to match calculations with representations and solving them, as well as applying the column method with base 10 support. Throughout the lesson, students engage in discussions about place value and the methods used for addition and subtraction, ensuring a comprehensive understanding of the concepts taught.