tales from the chalk face

So I spot a pupil with his iPad out when he should be working through some (paper and pen) revision questions. I head over ready to chastise him, but notice that he’s not on Facebook, Snapchat or anything else he shouldn’t be, but had gone to the BBC Bitesize website to help him with his question: he had to find the perimeter of a semi-circle.

My ire swiftly subsided. Seeing I was busy helping another pupil, he’d used his initiative and rather than wait for me he had helped himself by looking for help on the excellent BBC Bitesize website.  I engaged him about his work, asking him to explain how he was going to solve the problem:

I found the perimeter of the circle using Pi r squared.  We were given the diameter, so I halved that to get the radius …

I cut him off. “How do we find the circumference of a circle?” I quizzed.

Pi r squared …

Interrupting him, “no, what does Pi r squared give us?” I asked.

Pi r squared. It says so here : “The perimeter of a semi-circle can be found using the equation π x r² “

I looked, aghast, at his iPad. I did a double take and began to doubt my own ability.  I have huge respect for the BBC Bitesize websites and they are a great resource for students. But this was simply wrong.

We all make mistakes, but the BBC?

As I tell my students, it’s OK to make mistakes, its only by making mistakes that we can learn anything new, and this mistake did lead to an interesting class discussion and hopefully my students will remember the lesson better as a result.

But, I’m afraid, it has to be added to my collection of Maths Fails.

If you want to see the offending page for yourself, you can find it here.  I have reported it to the Bitesize team at the BBC, hopefully they’ll correct their error before long.