SUBTRACTION ACTION

In our class text book (which you don't absolutely need to have read to understand or contribute to this blog) the author describes three basic uses for subtraction, taking away, separating, and comparing.  The author goes on to illustrate and model six practical uses for subtraction.  These are 1) taking away a subset from a set, 2) separating a set into two disjointed sets, 3) comparing two sets, 4) taking away part of a length, 5) separating an area into two parts, and 6) comparing two lengths.

I really like how the uses are broken down and defined for me.  It allows me to simply move on to thinking about how I could help students make connections to subtraction concepts.  The modeling and illustration in the book points to how a teacher would want to model these concepts for students so, as a teacher, I would set up manipulatives at stations for students to explore each of these uses and get practice writing down the equation or equations that would go with their particular problem/solution.  I would then move on to having the students, as the book suggests, come up with their own subtraction-based story problem and solution.

After that, as a means of reinforcing the concepts, I would try to implement some sort of project-based learning math activity, the level of involvement being appropriate to the developmental level of the students.  I mainly go off on this tangent because, from what I know, project-based learning (also known as inquiry-based learning) is a way of learning that give students ownership over their learning.  I found a few websites that are helpful for getting my brain around the concept of project-based learning in general, and project-based learning for math specifically.  Here are the links.

http://pbl-online.org/About/whatisPBL.htm

http://www.suite101.com/content/project-based-learning-activities-in-mathematics-a142678

I know that all kind of branches off into the realm of what would be learned in a method class so, for discussion purposes, I am wondering what kinds of practical uses for subtraction would students find meaningful and interesting?  In other words, why might an elementary student want to take a subset away from a set, or separate a set into two disjointed sets, or compare two sets, or take away part of a length, or separate an area into two parts, or compare two lengths?

Also, I found this video interesting.  It presents a philosophy and a few ideas on how to make math relevant for elementary students.  One of its main ideas focuses on how elementary students are not ready to connect math with "real-life" scenarios as an adult would define "real-life" scenarios.  How does that idea fit with the above question?