Addition and subtraction - Subtract a two-digit number from a ​three-digit number crossing 10 or 100​ - Worksheet

The worksheet in question is designed to help Year 6 students master the skill of subtracting a two-digit number from a three-digit number, particularly when this involves crossing tens or hundreds. The National Curriculum objective is to add and subtract numbers with up to three digits, using the formal written methods of columnar addition and subtraction. To achieve this, students are provided with differentiated sheets, teaching slides, Base 10 blocks, and place value counters to aid their understanding of the column method and the concept of exchanging. Vocabulary terms such as 'add', 'subtract', 'column method', 'exchange', 'formal method', 'hundreds', and 'tens' are central to the lesson, ensuring that children are familiar with the key terminology.

During the lesson, children will focus on the position of numbers and their place value to correctly perform the subtraction. The process begins with exchanging one ten for ten ones, then one hundred for ten tens, before moving on to more complex subtractions that require exchanges in both columns. The use of concrete resources like Base 10 and place value counters allows children to physically exchange and visually understand the link between the concrete and the written column method. The worksheet also includes reasoning and problem-solving questions where children must identify and correct mistakes in given calculations, further deepening their comprehension of the subtraction process.