This week students will extend their work with ratios and proportional reasoning as they formalize their understanding of what it means for quantities to be in a proportional relationship. They formalize these relationships by writing equations to represent them, and connecting the constant change to a straight line on a graph. We discover that a proportional relationship will also go through the origin (0,0) of a graph and discuss why this happens.Students can already determine whether quantities in a table form a proportional relationship. They use these knowledge and skills throughout this unit as they learn that proportional relationships can be described using a constant of proportionality (unit rate) that appears in their equations. In 8th grade this idea is connected to the concept of slope.
I have been teaching 7th grade Mathematics for 10 years. I have worked at two IB MYP schools, one in Houston, Texas, and at West End Middle for 8 years. Please feel free to email me if you have any questions, comments or concerns.