Blend all the ingredients together in a saucepan. Cook the mixture slowly (here's where an adult should help), stirring constantly in til the clay pulls away from the side of the pan and you can no longer move the spoon.
Remove the mixture from the pan and, after it cools a bit, knead it until it becomes smooth and pliable.
Store in a zip lock bag or tightly sealed container to keep it fresh. If for some reason it does dry out a little, add a few drops of oil and water then knead it again to make it as good as new.