Column[{Row[{InputField[Dynamic[x], Number]; x = RandomInteger[50],
"+", InputField[Dynamic[y], Number]; y = RandomInteger[50], "=",
InputField[Dynamic[z], Number]}],
PopupWindow[
Button["Click Here"], {Dynamic[MatchQ[x + y, z]],
Button["Reset", DialogReturn[***Refresh[]***]]}]}]
I want to go back to the beginning when I press the button, but I don't know.
Still, it's fun to know one by one.