In high school, when learning maths I always asked ‘how am I going to use this in the real world?’. Which I never asked for English or Literature or things like that. But maths I saw as something which seemed useless at the time of learning. That it should be be justified.

Now, in my adult life I do use the more complicated bits of maths occasionally, stuff that I didn’t think I would ever use, and probably proclaimed as such in maths classes.

Image by Morley41Wiki (Own work) [CC BY-SA 4.0], via Wikimedia Commons

One part of maths education that I do value that was drummed in during all the lessons was ‘show your working’. I used to show a lot of my working, going vertically down the page, especially in algebra, where each step allowed you to work it out.
I liked that showing your working allowed you to work out where you made a mistake by working backwards.
It’s something I continue to this day, when working out stuff, I reverse my final result to work out if it still makes sense, if the result reflects where I started, etc.

Pythagoras’ Theorem a^2 + b^2 = c^2, is something at the time I never thought I’d need. But it’s something that I have found I’ve needed to use very occasionally. And needed to use the sine, cos and tan...uh...things. I was working out angles and couldn’t actually remember all of that. I got the three measurements of a triangle but then needed to get online to work out the angles. But I got more than halfway there.
Although one thing I don’t understand how to do, and distinctly recall being told ‘don’t worry you don’t need to know’, is how to do the square root that you need to do to get the final answer out of Pythagoras’ Theorem.

The other day I was trying to work out the area of a back garden. I’d used Google Earth to gain the measurements, but then needed to work out the area. Of a garden which isn’t a regular shape. After copying out onto a piece of paper to help visualise it better than on Google Earth it’s a rectangle and a right angled triangle. At that point I realised that again, high school maths actually works in the real world. Base x Height / divided by 2 (or as I remember it in my mind ‘base times height over 2’) for the triangle and length by width for the rectangle.

I feel like I want to find all my maths teachers from high school and say, thank you, some of the stuff you taught me did stick in my mind and I have used it, in the real world.