what is 4 5/6 plus 7 5/6?
[ 4 + 5/6 ] + [ 7 + 5/6 ] reorder as
[4 + 7 ] + [ 5/6 +5/6] =
11 + 10/6 =
11 + 1 + 4/6 =
12 + 4/6 =
12 + 2/3
