# VNPSs to the rescue!

This month I have a student teacher teaching my two grade 10 classes each morning. He’s been doing a great job trying out the spiralled curriculum & activity-based teaching approach that I use. He’s also continued using the visibly random groups (VRGs) & vertical non-permanent surfaces (VNPSs) that I have set up in my classes. Today we had a moment that really cemented for us why the VNPSs are so powerful:

A bit of background first. This year I’m teaching the primary trig ratios using trig trainers & a trig table. The trig trainer provides the sine & cosine values for a right triangle with a hypotenuse of 1. Students then use similar triangles to solve for missing information like this:

So far we had covered how to find missing sides, but not yet how to find missing angles using this method. The students had all the knowledge they needed to do so, there was nothing new to teach them besides how to apply their knowledge in a way to find a missing angle.

So yesterday my student teacher started his lesson by putting this problem on the board:

He asked the class questions about how they used the trig trainer to solve for missing sides (activating prior knowledge) to elicit ideas about similar triangles and scale factors. He then asked them how they might use the same ideas in order to solve this problem.

Crickets.

Nothing.

There were a few awkward minutes while he waited for them to figure out how to apply their prior knowledge to this new example type. He tried rephrasing his question but they weren’t giving him anything. They weren’t willing to venture a guess out loud. He was hoping they would suggest to him the method to solve for the missing angle & he would solve it on the board for them (direct teaching).

But I suspected that if asked them to, most of the students could solve the problem based on what they’ve learned so far, even if they couldn’t verbalize how to do so (or weren’t willing to verbalize it). So from the back of the room I piped up & suggested sending the groups to their assigned vertical surface (each group has a blackboard or whiteboard space assigned to them). My student teacher obliged & sent them to their boards.

Within one or two minutes a couple of the groups were solving the problem – using the exact method that my student teacher hoped they would explain to him in the earlier discussion. The groups that didn’t figure it out right away looked at the boards of those groups that had & quickly caught on to the idea and started solving themselves also. Here is the solution from one group:

Once most groups had solved it, my student teacher asked them to return to their desks & consolidated their learning with the whole group and then assigned some practice problems.

This experience really drove it home how beneficial the vertical surfaces are. When asked to explain orally how to solve the problem, students were not able. But working on the problem at their boards, most groups solved without having to be taught how to do this specific type of problem. And those that didn’t get to the final answer were still able to see the full solution presented, and done so in multiple ways by different group.

So powerful!