Okay... So what you have to do is make this a algebraic problem.
4x= 2/3
Whatever you do to one side you have to do to the other side.
1. Divide x by 4
2. Divide 2/3 by 4
3. Put everything together
Once all is put together you final solution should be...
x= 1/6
or
1 load of stone is 1/6 tons