With school almost out, the kids are going to be bored within a week of summer with "nothing to do." Try taking them to a library and getting them their first library card.
Also, incase you didn't know: Cunningham Art Gallery on 18th & R is open free to the public every third Friday of the month. Both library and art gallery is indoors and air conditioned when it is hell-hot outside.
If you know of any "cheap" or uncomplicated activities for kids, please post them. Like to hear from you. You may know something I (and other readers and bloggers) don't.