Ratio - Calculating Ratio (Activity) - Presentation

The concept of ratio is a fundamental mathematical principle that is explored through interactive activities using counters and bar models. In the activity, students are tasked with calculating the number of counters based on given ratios. The lesson begins with an exploration of what the term 'ratio' means, encouraging students to discuss and understand the relationship between different quantities. For example, they are presented with a scenario where for every 2 red counters, there are 3 blue counters. The students use this information to determine how many blue counters there would be if they had a different number of red counters, such as 6, by using proportional reasoning and visual aids.

As the activity progresses, students delve deeper into the concept of ratios by working through various examples that require them to calculate the corresponding number of counters. They learn that if the ratio of red to blue counters is 2:3, then there will always be 1.5 times as many blue counters as red counters. This understanding is further reinforced through hands-on practice with counters and the use of bar models to visually represent the problem, making the abstract concept of ratio more concrete and understandable. The students are then challenged to apply their knowledge to different ratios and total numbers of counters, such as determining the number of red and blue counters when given a total count and a specific ratio, such as 5:2 or 3:1. The activities culminate in a discussion about how counters and bar models aid in understanding ratios and the significance of the order in which ratios are presented.