Addition and subtraction - Subtraction crossing 10 - Worksheet

The educational resource provided focuses on the concept of subtraction, particularly when it involves crossing the number 10. This worksheet is part of a series of lessons aimed at Year 6 students and aligns with the National Curriculum objective to read, write, and interpret mathematical statements involving addition, subtraction, and equals signs. The objective is to add and subtract one-digit and two-digit numbers up to 20, including zero. Students are encouraged to use practical equipment such as Base 10 blocks to visually differentiate between hundreds, tens, and ones to aid their understanding of the subtraction process.

During the lesson, children are introduced to the strategy of partitioning to subtract numbers that cross the threshold of 10. They start by using concrete manipulatives or pictorial representations such as ten frames and number lines to model the strategy. The ultimate goal is for children to be able to use this strategy mentally. The worksheet provides examples where the starting numbers are circled and the numbers are already partitioned, guiding the children on how to cross 10 on a number line. As they progress, they will encounter incomplete questions, which they must solve using the clues provided to write the correct number sentence. The lesson includes key questions to encourage critical thinking, such as how partitioning helps with subtraction and the role of counters and number lines in visualizing the strategy.