It really depends on the age, size and behavior of your frogs. Older and bigger frogs will eat larger amounts, probably 8-10 medium sized crickets in 10-15 minutes. In addition, if you notice that your frogs moves around often, it means they are more active and perform more metabolic functions, and therefore may need more energy than the ones that just sit in one place for days.

I agree with the above suggestions that you should feed your frogs as much as they can eat in 10-15 minutes, and always make sure you watch as your frogs eats. If they shows signs of stress or he does not want to eat, try again later. Also, I recommend feeding them with tweezers to monitor how many crickets your frogs eat, to see if he is growing and eating his usual amount or more, or if he is falling sick and eating less than usual.