Finally, a game that allows you cheer that most cherished of subjects: math. With a shiny new facelift, exploding tiles, and the ability to rotate the board 90 degrees, Drop Lift v2.0 is a major upgrade to the original. Link together chains of numbers that add up to nine in this awesome block-dropping puzzler.

DropSum is an elegant puzzle game by Nick Harper, who describes it as a cross between Tetris and Sudoku. Burst bubbles and form complicated chain reactions by forming groups that add up to 9. If you ever find yourself yearning to lay down some damage with the power of sums, this is as good as it gets.