If a thermometer is calibrated to the nearset degree, what part of a degree can you estimate the temperature it measures?
Doesn't it depend upon the spacing of the degree marks.
Spaced like this ||
or like this |     |
would make a difference, wouldn't it?
For the usual spacing I have seen for a thermometer for use in a lab, I would think about 0.5 degree for one that reads -10 to 360 C.