Nobody can answer such a question, there are too many unknowns. How many food items are in each package? How large are the animals? What is the temperature? (They eat more when warm.) And even if we knew these things, there is still a lot of variability between animals.
Is your concern how much the animals should be eating, or how much money you need to spend on food? If it's cost, there may be less expensive foods you could use, such as earthworms from outdoors.
The important thing is that the animals stay at a healthy weight. There should never be leftover food in the tank for any length of time (including live crickets, which can munch on the sals' skin). Feed them as much as they want, but not so much that there are leftovers.
