As teachers we lose sight of just how much we condition our students. Despite our protests of “they haven’t learnt anything”, they have learned much: good, bad, and distracting.
I’m arguing their inordinate focus on numerical answers, significant digits, and the number of decimal places they dwell on, all comes from us. We use this focus on numbers as a convenient way to measure success, theirs and ours.
Obviously, there is a time and place for unit conversions and the details of numbers. How else could you do experiments and uncertainty calculations without these skills?
But when they are learning new concepts and equations, with an expectation of solving related problems, these are learning distractions for them, and teaching distractions for us.
One-decimal place answers
I skipped over one of the no calculator options – it wasn’t necessary for the video – that being how to generate simple one decimal place answers. I’m talking about mental calculations resulting in one decimal place answers without any need for rounding.
For example, instead of
Why not change, i.e. contrive, the numbers to be
Test design
In a future Chapter 4 episode I’ll explain how these ideas translate into test design; but as I mentioned in the video take some time now to reflect on a recent test you created. Count how often your students have had to deal with these distractions, how many calculator buttons did they have to press under time constrained stress to get “the answer” …and were they necessary?
I’d suggest very few of them.
The equations
PS the solution to the first problem comes from the equation
and the second solution uses the equation
solved for V.
