This is a clever idea with mediocre, at best, graphics.
A deck builder in which the player must play from a random hand of cards whose play cost is paid from combinations of somewhat randomly generated integers and the three operators: plus, minus & times. Not a game for the innumerate.
Its worst failing is the egregious degree of cheating by the computer opponent. Few things are more annoying than apps that are not bound by the same rules as are the player.
We expect some cheating by computer opponents. Too much of it is just plain unpleasantly
So a five star game demoted to three stars for poor sportsmanship.
...rmk about Calculords