for an easy conversion to decimal degrees
divide minutes by 60 and add to degrees 2*45' = 45/60 =.75 + 2 = 2.75*

To change decimal degrees to d*min' multiply the decimal portion by 60 and result is minutes then write the degrees.

2.5* = 0.5* x 60 = 30' + 2* = 2*30'

By converting to decimal degrees and back converting back to minutes it makes it easier to determine how much angle needs to be adjusted.

For examples above
2.5* - 2.75* = (-)0.25*, then multiply 0.25* x 60 (to convert to minutes) or (-)15'.
One can also include seconds if needed, or desired, but this takes additional steps that I could explain if anyone needs to know pm me.