Group the fraction, decimals and percentage
http://www.mathplayground.com/Decention/Decention.html
A game of additions and percentage
1) Move several things from the left to the counter.
2) Find the total of all the things. (Without discount)
3) Find the discount of the total.
4) Find the money we should pay after the discount
http://www.mathplayground.com/percent_shopping.html
Maths Olympic
http://www.mathplayground.com/olympic_math1.html
Maths Millionaire
http://www.mathplayground.com/math_millionaire.html