ThePrimes, Lite

Many generations of geeks have contemplated the eternal question on how to create an ultimate geek game.
And finally, geek ladies and gents, we can proudly say we did it! ThePrimes, Lite is the name of the game.
Anyway, this game is all about Prime numbers and the use of  little grey cells whilst creating Prime number formulas from numbers and operations on a 5x8 grid. You should select numbers and operations in alternate order to form prime number expressions (for example 4*1+7 is 11 = prime number). As your score increases, game speed is faster.
Check also full version of this game.