When I took physics, all of our measurements were only accurate to 3 digits for most things. Using a calculator that's good to 8 or 13 digits will actually throw off your calculations and give you bad answers. My physics professor required, and even supplied, sliderules. These worked to 3 digits and made us do a little thinking on the side. We also did open note/open book tests in that class and were allowed to use any reference or resource in the class except other students. This included, as one student figured out, the professor himself. A little unusual but Mr. Gaskins was the most awesome physics professor of all time.
Just my 0.02 USD worth.