How many slices is 1 oz of cheese?

Depends on the slice! If you have the package in front of you, look at the calories per serving and also the amount of servings. For example - if the serving size says 1 oz, and there are 90 calories per serving size, and the package size is 8 oz, then if you slice your entire package of cheese into 8 slices, each slice would be approximately 90 calories. If you sliced the cheese into 12 slices, each would be 60 calories