If you would like to calculate 2/3 * m - 1 1/6 + 5/6 * m - 1 1/3, you can do this using the following steps:
2/3 * m - 1 1/6 + 5/6 * m - 1 1/3 = 4/6 * m - 7/6 + 5/6 * m - 4/3 = 9/6 * m - 7/6 - 8/6 = 3/2 * m - 15/6 = 1 1/2 * m - 5/2 = 1 1/2 * m - 2 1/2
The correct result would be 1 1/2 * m - 2 1/2.