...which is probably what the compiler does for you.
I don't think it converts divisions by powers of 2 into right-shifts...R
Write a test sketch, the proof is in the pudding test ....
NB: The result from analogRead() is not a value (as we would like to think of it when measuring something), its an index. Its an index to a bin number in which the measured value fits, and there are 1024 bins (which has to represents the whole range of values you want to measure).
2. 5V (equal to VREF = Full Scale) at the input of ADC ----> ADC produces 11 1111 1111
What are these two known points
So then you go and list three points !