We needed to work on this with GCSE resit groups:
Dry, dry topic. Maybe, but here’s what I did, and then what I’m gonna do next time.
Throw this up:
Give them random shhhtuff to measure
Graph it in Desmos:
Make an estimate of the conversion factor
Repeat for other data
Try some conversions using the correct ratios.
Two (large) issues occurred
- Students can’t measure in inches
- Students mis-scaled their axes
So, the second is worrying; axis starting at one (or two!?) and axes with inconsistent spacing make it all but impossible to predict from the graph and gave some students the conversion that 1″ is negative cm or other such nonsense. I think that this realisation MAY have have had an impact, as the next batch of graphs they drew, I saw no similar issues. However; there students should be able to draw correctly scaled axes. Starter perhaps for tomorrow’s lesson?
The first is less worrying for the exam content (they will never be asked to measure in inches) but more worrying in terms of LIFE. I see the start of next lesson also including reading scales…
So what will I do differently next time?
- Start the lesson off with scale reading
- Give them the axes – ideally they’d use graphic calcs and lin reg it and such, but that’s waaay beyond what these students need and several lessons to get them to use the calculators!
- Give them more opportunity to measure. I’m thinking scales in the classroom and maybe Google Earth to measure distances? – I feel stations coming on…