Movie time 1
Set the kids up with movie snacks and a good flick. Go on and let them watch Frozen for the 500th time. I promise you they won't mind. If you don't have a second TV, you can do it on a tablet or computer.
Get lots of boxes 2
This is great for younger kids. Younger kids love boxes. They go nuts for them and it is amazing how long they can play with empty boxes, so hook them up. Get a bunch of boxes and don't even tell them what to do with them because I promise you they will find the fun on their own.
Send them camping 3
I'm not suggesting you actually send them out camping, I mean set them up with an indoor camping scenario. Put up a tent, give them props and let them play.
Let them make art 5
Get art supplies they've never used before because the novelty will keep them interested and have them make art. Be creative, give them glue, beads, strings, noodles, beans, cardboard, markers, popsicle sticks and see what they make.