Fun experiment: At the very beginning of the vectors unit, just after describing what vectors are, ask the students what they think should be the answer if I add these two vectors. Stop talking, and take pictures of what they think “adding” could mean for vectors. Some students have clearly heard of it before (some in physics class), but I love the variety of answers presented. Not necessarily an intuitive idea…. Just wait until we get to vector multiplication!

I’m always fascinated by the parallelogram method – occasionally students find this easier, but I fail to see why it would be more intuitive. I think it’s really nice for showing how the two vectors affect the resultant simultaneously, but that never seems to be student reasoning for their preference from the beginning. I’m currently doing a vector unit and this is always such an interesting part of this vector introduction to me.

I suppose it’s a nice reminder of the communitivity of addition, and it might be more intuitive for physics examples where two vectors are “pulling” an object, but yea, agreed.