Weight and volume - Introduce weights and mass - Presentation

The concept of weight and mass is introduced to learners through engaging and relatable scenarios. Initially, the lesson explores the idea of how heavy or light an object is, using everyday examples to illustrate the point. The narrative follows a postman whose bag of letters becomes progressively lighter as he delivers them, and his happiness grows in tandem with the decreasing weight. This concept is further reinforced through the story of the postman picking apples; as he fills his basket, it becomes heavier, and his satisfaction is linked to the increasing weight of his bounty. These stories set the stage for understanding the tangible sensations of weight and mass in real-life contexts.

Building on this understanding, the lesson shifts focus to the practical measurement of mass. Learners are encouraged to collect items in a basket or bucket, adding and removing objects to experience the changes in weight first-hand. The discussion then turns to how we can objectively measure mass, introducing the balance scale as a tool for this purpose. Through hands-on activities, students observe how the scale tilts with different items like an apple and a lettuce, and they learn to compare masses by placing various objects on the scale. The lesson culminates in an understanding that items can be heavier, lighter, or of the same mass, and that appearances can be deceptive, highlighting the importance of measurement. For instance, a larger present may not necessarily be heavier than a smaller one, as demonstrated by the surprising contents of the gifts: birthday balloons in one and a rock collection in the other.