Every parent knows that unsupervised kids can get into plenty of trouble online. They could unknowingly infect your computer with a virus, or even meet a child predator in a chat room. Kindergarten is a great age to instill safe internet practices in your kids.
As a parent, I'm always happy to find safe activities for my kids to do online, because if you make the computer the forbidden fruit, they will forever want it! So, keeping child internet safety in mind, educational activities are a great way to let the kids online. Plenty of parental supervision is always a good idea, but supplementing some of your homeschooling lessons with online resources is a great idea. You can find something interesting online to supplement just about any curriculum you're using at home, and it gives your kids valuable practice in navigating the internet safely.