Length and Perimeter - Subtract lengths​ - Presentation

In a series of engaging activities, students are introduced to the concept of subtracting lengths in the context of perimeter and length measurements. The lesson, which is part of a larger set of teaching slides, encourages students to find differences between lengths of various objects. For example, they may be asked to determine how much longer a chew bar is compared to a pencil, with the aid of visual aids and part-whole models. These models are particularly useful in helping students visualise and solve subtraction problems, prompting them to discuss how such models can be applied in different scenarios.

Further activities challenge students to apply their understanding of subtraction to real-life contexts, such as calculating the amount of rope left after cutting a piece or finding out how much wool remains after knitting a scarf. These problems often involve mixed units, requiring students to convert metres to centimetres and vice versa, thereby reinforcing their skills in dealing with different measurement units. The lesson also includes reasoning tasks where students must calculate the remaining distance in a bike race or compare the lengths of vehicles, enhancing their critical thinking and problem-solving abilities. Students are encouraged to discuss their methods and share which models they prefer, fostering a deeper comprehension of the most efficient ways to subtract mixed units.