In today’s seventh-grade mathematics lesson, the focus was on understanding averages, specifically the mean, mode, median, and range. The mean, often referred to as the most common type of average, is calculated by adding all the numbers together and then dividing by the number of entries. An example was provided using five data points: 12, 18, 9, 11, and 15, where the total was 65, resulting in a mean of 13 when divided by 5. The lesson emphasized the simplicity of finding the mean through practice and understanding its relevance in data analysis.