Started Linear programming today with one of my favourite classes. Ever since I read this post by Fawn I’ve been super excited about the activity and I ordered some extra bricks (thought apparently not enough to use up all my 2×4 bricks in sets) to make a full class set. (The packages my Lego order came in is another lesson in progress, thanks to @absvalteaching)
I knew that the students would solve the task as presented pretty fast, so (alongside adding another activity) I milked the intro a bit, made them name their company and got them hyped up before I threw (literally, not figuratively) Lego at them to solve it.
I played the awkward teacher game where I refuse to accept any answer they gave me without tons of explanation or evidence. I eventually let the off the hook once we’d discussed the range of possible combinations and looked at a way to record it (table). I have to say at this point I pretty much shoved the idea of variables into them – but they followed the table and liked my use of black magic (elsewhere known as desmos.com) to graph the inequalities.
We took a journey through time and space to some years later in the life of their furniture store (now a chain) and presented them with an updated problem that they couldn’t solve through trial and error.
I made them work in pairs to come up with the constraints and objective function and then got three students to explain to those who didn’t quite get it.
This is where @bobloch comes in.
I split the class in half and assigned each a constraint to work on. I gave each half 48 points (the same 48 co-ordinates) and asked them to sort them into those points that satisfied the constraint and those that didn’t.
I then made them do this:
That’s right, STICKERS. They stuck a couple of points each in approximately the right position, red for one constraint, yellow for the other.
I then employed sorcery to bring up our feasible region
Finished up with using the objective function to work out we needed 200 chairs and 300 tables, and then wrote a summary for their notebooks.