I don't think some people have noticed something about the scales, there's a pattern.
For the major natural scales you start from the bass note of the chord and go 2212221.
For example, the A major scale starts from the bass note in the sixth string fifth fret

E------------------------------------------4-(5)-----
B------------------------------------5--7------------
G---------------------------4--6--7-----------------
D------------------4--6-(7)-------------------------
A---------4--5--7-----------------------------------
e-(5)--7--------------------------------------
       2  2  1  2  2  2  1  2  2  1  2  2  2  1  

For the minor scales, the pattern is 21221222.
Try it with every chord and you'll be a master!