What to do about poor retention?

I was really frustrated today by my students’ poor retention of information. We were reviewing for our final exam in Geometry today and half of my students could not find the area and circumference of a circle. The problem was not obscured by context in any way, I just drew a circle, marked the diameter as 12 meters, and asked for the area and circumference. Students were working on personal white boards and as I walked around the room, I saw lots of blank boards. A few students were confused by the fact that you have to first find the radius (6 meters), but many students just didn’t know the formula for the area and circumference of a circle.

We have practiced finding the area and circumference of circles in various circumstances at least a dozen times. We measure circles, drew circles, made cylinders out of cardboard. A few times we just practiced doing exactly the task that I described. It is so frustrating that the information is just not sticking.

And this is just about finding the area and circumference of circles. Just imagine what the retention was like for other topics. It was pretty sad. It made me feel like a super huge failure as a teacher. I know part of the problem is that over half of my class does zero homework–without extra practice, there’s not enough repetition for  things to sink in. But still, I thought by now students would know the formulas for area and circumference of a circle, even without doing homework.

What do I have to do so that students will retain information better? And I’m not referring to some of the more detailed facts (like the fact that the intersection of the angle bisectors in a triangle is the incenter), but very basic and fundamental ideas and facts.

2 thoughts on “What to do about poor retention?”

1. gnart says:

Have you tried rapping? In all seriousness, sometimes the weirdest ideas stick best with certain students. When I was teaching my kids how to multiply two numbers together, I told them a camping story about the numbers on the bottom row (i.e. jerks on the bottom bunks) kicking (i.e. multiplying) the numbers in the top row (i.e. innocent campers wanting their sleep). Surprisingly, it actually worked because they loved it when I said the word “jerk”! Weird. Anyway, I just think it would be HILARIOUS if you did something like rapping. 🙂

2. Anonymous says:

I had a similar problem two years ago in my 7th grade. I resolved testing them orally on geometric formulas everyday. They hadn’t any problem in understanding formulas, they just didn’t study them. In a few weeks the problem was solved.