Well done on making a subject interesting and memorable.

Always take the opportunity for something different...

My most memorable teacher was a maths teacher, and I didn't like maths much although I could do it ok.

He used to do interesting things, like take us to the park when the monarches were migrating. And we'd sit there with our calculators and formula books working out cosines and tangents!

You have given your students a day of learning they will most likely remember, a day that will influence some of them over their lifetimes.

They will not only be calculating and estimating gradients, they will also have a new respect and understanding of cyclists and runners who charge up these inclines - and a deeper understanding of you.