How old are your kids?
Turtles care-well set up is expensive as they require special lighting and good filtration and more water cahnges than a fish tank.
Fire belly toads easier and cheaper. Get a 10 gallon tank. Find a tupper ware bowl or new/clean paint tray, that fits half the tank and fill with water. Other half fill with mulch from petstore and/or moss sold for amphibian cages. Maybe a spider plant or pothos.
Every 2 to 3 days drop in 3 crickets per frog. ( I buy crickets when needed a few at a time and dump whole bag in so I dont have to touch them.)
Change water container weekly and every day or every other day lightly spritz whole cage with a water bottle with distilled water.
Thats it. If its cold where you are you might need a heat lamp, but temps of 65 to 78 is fine for the frogs.(My house temp.)
A little tougher my tank has water in one side with a small filter rocks piled high on other side and covered with moss and mulch.
Once a week we use a cup to empty water and pour more in, once a month we replace the mulch and moss.
To me thats easier than hampsters and the like, because you dont ahve to check their water bottles or feed every day