It's tough. I feel like by the end of the day, I'm always exhausted just from answering all the questions and helping with all the projects! I've found that structured activities that stimulate their minds help a lot. Music lessons, science camps.....whatever they are interested in doing. You're never going to completely get a break, but that's a good thing. Just try to remember that it's good for a child to be inquisitive....even if it sometimes makes you want to pull your hair out!