What does 2/6 + 2/3 + 5/6 + 1 1/2 + 4 * 2/3 =

By following PEMDAS, you can work out that you should multiply 4 by 2/3 first (even though it isn't at the beginning of the equation):
4 x 2/3 = 8/3

Then, it will be much easier for you if you make all the denominators the same.
2/6 = 2/6
2/3 = 4/6
5/6 = 5/6
1 1/2 = 9/6
4 x 2/3 = 8/6
Then, add all the similar fractions together:
2 + 4 + 5 + 9 + 8
            6

So, your answer is 28/6 = 4 4/6 = 4 2/3 
Hope this helps :)

She will need 5/8 bags for each square yard.