Make Math Moments Academy › Forums › Mini-Course Reflections › The Concept Holding Your Students Back › Lesson 6-3: Digging Into Thinking Of Ratios As A Multiplicative Comparison and Composed Units – Discussion › Reply To: Lesson 6-3: Digging Into Thinking Of Ratios As A Multiplicative Comparison and Composed Units – Discussion
MemberNovember 14, 2021 at 5:42 pm
For me, I really appreciate the separation of the ratio (composed unit version) as being the linked growth between two (or more) quantities (often distinct or different attributes), while the RATE is the amount of one of these quantities per another. And I particularly appreciate the idea that the RATE doesn’t happen until after the partitive division has be “completed.” That otherwise, it’s not a rate – it just a method to calculate the rate — which can be written as a fraction.
I’m wondering how this idea of multiplicative comparison and composed units can fit into the idea of percents/percent increase and decrease. I am feeling that the increase and decrease problems will lend themselves more towards the multiplicative comparison kind of relationship, but I also have had a lot of success as thinking of percents on a double number line, which would be more connected to composed units (where, for example, $ and % are the two units).