Good luck counting...
Rather than using numbers, a number of people use volumes. Now this is a little different depending on what size container you hatch your Artemia from, but it is fairly close and can be modified if need be.
For a 10 gallon tank, I would feed about 10 ml of the artemia/water, twice daily. Keep in mind that the more feeding you do, the more water changes you may have to do because of uneaten food and the increases in nitrogenous waste products. You just have to play around with it for a bit to see what works best for your personal setup.
Greg