Addition and subtraction - Subtract a two-digit number from a ​three-digit number crossing 100 - Worksheet

This set of educational resources provides a comprehensive approach to teaching children how to subtract two-digit numbers from three-digit numbers, particularly when crossing the hundred boundary. The National Curriculum objective is to enhance mental addition and subtraction skills, which includes dealing with three-digit numbers and tens. To facilitate this learning, differentiated worksheets, teaching slides, and number lines are employed as key resources. The vocabulary list for the lesson includes terms such as 'add', 'subtract', 'multiple', 'mental methods', 'exchanging', 'patterns', 'columns', 'calculations', 'compare', 'efficient', and 'backwards', aiming to familiarise students with the concepts and language of arithmetic.

Through a variety of activities, the children learn to subtract multiples of ten from a three-digit number, with some examples requiring an exchange. This can be demonstrated using number lines and part-whole models to visualize the process. While the column method is an option, emphasis is placed on more efficient strategies, such as counting backwards in tens or using the hundred as a reference point to support mental calculations. The lesson progresses with reasoning and problem-solving tasks, where children apply these strategies to subtract multiples of ten from three-digit numbers, both on number lines and through word problems. As the difficulty increases, children are challenged to solve more complex problems and share different methods of subtraction with their peers, encouraging a deeper understanding of the concepts and fostering collaborative learning.