​what is 6 2/6 - 2 4/6 =

[6 + 2/6]   =    [5 + 1 + 2/6 ] =  [5 + 6/6 + 2/6]   = [ 5 + 8/6 ]

So

[6 + 2/6 ] - [2 + 4/6]  =

[ 5 + 8/6] - [ 2 + 4/6] =

3 + 4/6  =

3 + 2/3