6748
6 * (7 - 4) - 8
(6 * (7 - 4)) - 8
6 * 7 - 4 * 8
(6 * 7) - 4 * 8
6 * 7 - (4 * 8)
(6 * 7) - (4 * 8)
There are 6 methods.