Last year from a workshop I learned of a fun activity with which to introduce volumes of revolution to my class. It involved candy, the kids seemed to get it. They loved it. We all walked away with smiles on our faces. But then they got home and couldn't do homework involving revolving regions about various axes. Granted in class, we only went through 3 examples, I talked them through it all the while giving them a chance to process it. But still, no.
This year, I was looking through my files and came across another way to introduce volumes of revolution. It's (free) from www.mastermathmentor.com . And there are TONS of calculus AB and BC (did I mention free) worksheets there. I'd hesitated using it before because it looked TOO LONG to get through in class. Then the homework was TOO LONG. Hey genius :), just because all the problems are there, it doesn't mean you have to use them all.
I used this sheet this time. I slowly walked them through the 6 parts of example 1. I kept stressing the questions to ask yourself, and I weaned them off my help so that by the 6th problem they could do it by themselves. Then for homework I assigned them examples 2 and examples 3 (12 problems) from the class work worksheet. Wouldn't you know it. They all got it right. AND they could then go on and do more challenging problems. Success.
I keep having to teach myself that not every student can get by on just one to two examples to teach a concept. Some students need 5 or more examples. But then there's always the time factor and the other kids in class that can get it with just one example. Anyhow. I'm now excited because I've found a new effective way of teaching this topic.