You Know What Happens When You Assume

One of the many important steps in planning a lesson is to identify the assumptions in your plan. What are you assuming that your students already know? Trying to guess what your students do and don't already know can be tricky work, and if your assumptions are wrong, it can wreak havoc with your lesson in the classroom.

In Career Exploration, we're spending a few days putting together a college budget. We're calculating monthly expenses and determining how much financial aid the students will need for their first year of school. Coming up with the final numbers involves a bit of math, including some very simple algebra, which I assumed the students already knew.

Some calculations in the assignment required two or three steps to complete. Similar to the way accomplished chefs leave out "obvious" (to them) steps from their recipes, I left out some of the "obvious" steps in the calculations. I'd tell the students to "average" the numbers instead of explicitly telling them how to average the numbers.

Well – you know where this is going – assuming that the students had these math skills was a mistake. When I backtracked and explicitly explained how to perform the calculations, some of the students got frustrated and gave up early. This was a big problem because the later calculations depended on the earlier calculations, which some of the students didn't complete.

The obvious solution would be to teach the students the sequence of steps necessary to perform the calculations. However, that would be a huge mistake. The students wouldn't be learning anything at all; they'd just be following a series of detailed instructions. They'd be following all the steps to average numbers without really understanding what they were doing. Anyone could do that. The whole point of teaching is transfer. If students can't complete their own budgets outside of school without depending on a teacher to show them how, what have they really learned?

I think a more effective teaching strategy here would have been whole-part-whole. Next time, I'll start by introducing the (whole) concept of a budget. Then, I'll give them the specific problem (part; like averaging tuition costs), break them into cooperative groups, and ask them to come up with a solution on how to solve it. Then, I'll come back to the budget (whole) and show them how their calculations fit into the bigger idea.

This article was originally written during my first year teaching experience.