By Carol Costello and Bob Ruff, CNN “Isabelle, you're next. What card do you need to add to 10 to get what?"   Grade schooler Isabelle Hannon is learning how to add and subtract, but not in a classroom. She’s outdoors, at a beautiful Stillwater, Oklahoma park. She and her sister, Alyssa, are being taught … Continue reading Communal homeschooling on the rise