Sounds like a great opportunity to clean out your closet. Give them a box of your old clothes to play in-they can even put on a fashion show for you-break out the camera. When you're finished watching them, you can just box the clothes up and take them to your local donation bin. It's a great time of year for outdoors too. Maybe purchase a small plastic pool-even the 8 yr old will enjoy this if he doesn't have the option of a larger pool. You can pick up some water toys at the local dollar store. When my kids were small, we'd have lunch, lather on the sunscreen, and play in the water for about an hour-a little tub time afterwards to remove all of the sunscreen that was left over and then we'd lay in the floor and watch cartoons or a movie until we fell asleep for a nap-yep, me too-I had 4 little ones and it was exhausting! Another activity that we had in the afternoons would be my wonderful foot rubs! I'd place a towel on the couch and give each kid a dab of lotion. (usually the most active toddler got to have my feet in their lap) They would dab the lotion on my feet and legs and doodle/draw pictures in it. They were entertained within reaching distance and I could actually watch tv or flip through a magazine without having to wonder what they were into.
Good luck-I have 2 grandchildren now and know exactly how you feel! They have a big age gap though-grandaughter is about to turn 12 and grandson is 3 months-so we have to try on different options now. Usually when the youngest is down for his long nap of the day, I keep some really easy muffin mix or something on hand because my granddaughter likes to cook. I handle the oven part, but she does all of the mixing and taste testing! We have a blast!
R.