Image by D-Kav via FlickrI'm an engineer and sometimes mathematical calculation show up on my blog. In order to make it easier to do the math and for my blog readers to check the calculations themselves I looked for calculator gadget solutions. I have found two options that I like.
Maths-Whizz Scientific Calculator
This one is great for a blog or website and completely free. It has all the functions and features I crave. Had I had it college, I would have needed no other calculator. As for some of the pre-built features that other calculators have like converting units of measure, I don't need those. I'd rather convert them myself.
This one I liked too, but it seems to be best for a desktop uses. The other things is that it's not free - $15. Good freeware, however.