I had a standard slip stick and have used a circular one as well. They were nice but I have to admit I like a calculator better. A calculator made statistics endurable, barely. I did far better understanding the concepts of the statistical study than the mathematical crunching of the data and applying the proper formulae.
I'm one of the math challenged folks. It takes me a while to get the concepts and they seem to leave fairly quickly once learned. I did fine in HS Algebra and Geometry. I am able to apply the formula and theorems but do not have an intrinsic understanding of the symbology and it's relationship. After that I seemed to have lost it. Once I have the formula down I can use it but can't "visualize" mathematical concepts of any higher level. Taking HS physics was the first really big brick wall I hit and had to drop the class. It's a shame as I like science I just can't calculate it. My son on the other hand thought calculus was fun. He sure as hell didn't get that from his mom or I.
Folks have some kind of learning ability that they can exploit. Math just isn't mine. I'm great at intuitive things like understanding the relationships of the parts of a mechanical device but don't ask me to do much more than calculate the displacement.
