92.8.61.10: Elementary problem collection for children (2010-03-30 16:13) [#7595]

I'd like to give a small boy of 8 some elementary problems to solve with Drago. They'd need solutions and explanations in English. Gilles's links are helpful, but not quite right for present purpose. Does anyone have other links or collections they wouldn't mind sharing? With thanks! David, London.