freerice.com I really wanted to share something I've just found as it may help your primary school aged children with maths ect whilst helping them feed the poor. My 6yr old has a target off 1K grains of rice a week. Hopefully you find the website useful for times tables ect and your children get involved in it.
Let me know your kids high scores! There are also many different subjects including maths, times tables, English and much more.