Mass and capacity - Add and subtract mass - Planning

In the Year 3 Summer Measure (Mass) curriculum, students embark on a week dedicated to understanding and manipulating mass. The National Curriculum objectives aim to equip them with the skills to measure, compare, add, and subtract mass in different units such as kilograms and grams. The key vocabulary for the unit includes terms like scale, capacity, volume, litres, millilitres, and various comparison symbols. The specific lesson on adding and subtracting mass utilises resources such as worksheets and presentations to facilitate learning. Students are encouraged to use mental and written methods to solve problems, with the option of using concrete resources to visualise kilograms and grams. The lesson plan includes activities where children use a part-whole model to add and subtract two masses, ensuring they combine like units (kg with kg, g with g) for accurate calculations.

The lesson's activities are designed to reinforce the concepts of mass addition and subtraction. For instance, children might use the part-whole model to combine the mass of two different items, such as adding the mass of a jar and its contents. They are also presented with real-world problems, such as determining the mass of cookies in a jar by subtracting the mass of the empty jar from the total mass. Visual representations, like bar models, are suggested as tools to help with understanding. The lesson concludes with reasoning exercises, where students apply their knowledge to solve problems involving the mass of parcels on balancing scales and the mass of fruits like pears and peaches. The plenary includes a reflection on the skills learned, with a focus on using part-whole models and combining like masses, as well as identifying any areas of difficulty and strategies that aided learning. Differentiated worksheets allow for tailored learning experiences, catering to students working towards expected levels and those capable of greater depth understanding.