Grid Club
Founded in 2001 by England's Minister for Schools, GRIDCLUB.COM is an award-winning, UK-based online educational site for kids ages 5-12. Through games, activities, and other interactive features, the site offers a vast curriculum that includes literacy, math, science, geography, and lots more. There's also a reference section, a teaching curriculum that includes lesson plans and worksheets, as well as a parents' area. The content is updated regularly and the subscription fee is currently about $44 a year.
Whyville
Kids can learn many things in Whyville, from science and data analysis to managing bank accounts and healthy diets. Kids might start by playing science games, such as exploring what causes seasons and how winds affect hot air balloons, or making objects spin faster (such as an ice skater). They can gather data about creatures in the ocean and compare it to other kids’ observations. They manage their avatar’s diet, exercise, and immunity from viruses. Kids can even study how diseases spread in Whyville. Activities may require help, but most empower kids to pursue science in ways that apply to everyday life.