Remembering formula – teaching for recall


So, today was the first day back to school after the Christmas holidays – back to the grind in 2012. Today was a pretty busy day – like most UK schools every day of the week is different for me. I thought I’d try to think of one thing I could record on here each day for a while, both as an exercise to encourage me to keep thinking about my practice in deepest, darkest January and to remember things I have done that have worked. 
I had my Year 9s today and we started to think about circles.  We spent some time drawing them, labelling the parts and then measuring to try to find any pattern. Most were on board and, even with the dodgy measurements, we could see and explain that the diameter was twice the radius and also that the circumference was about three times the diameter. We had a conversation (maybe it was more a lecture, but they were interested, honest!) about Greeks, irrationality and pi. I introduced the formula C=pi*d and we thought about that and saw how that might help with any circle we might meet for the rest of our lives. 
Over the years, I have tried a number of ways to help students remember this formula and the area formula. Today, we did my favourite – hotter/colder!  Here’s how it works:

  • Pick an object to hide
  • Send a student out of the room
  • Hide object
  • As student enters whole class chants “c equals pi d” on loop
  • Closer = louder, Further = quieter

Simples. I liked it and the kids seemed to get it. I bumped into one later in the day and said “C equals” to be met with “pi d”. I know on its own it’s not teaching for understanding but it was fun, they understood it and normally they remember it. I see them tomorrow, so let’s see how that goes!

Do you have any innovative ways to remember formula? Any classic songs you sing or play for your class?