Sum X is a simple yet complex numbers game available on Android developed by Kidga: free puzzle games. The game is free to play and falls under the educational subcategory of games. The objective of the game is to collect as many sums as possible on each level. The game consists of a set of levels, and the aim sum to collect is shown in the header. You must select adjacent numbers within a horizontal or vertical line that together are equal to the aim sum. The game ends if no moves are possible, and the sum of all collected sums is less than the sum of numbers left on the field. The game also allows you to shuffle numbers three times per game using the shuffle button.

Sum X is an ideal game for those who are eager to train their math skills. The game's rules might not be easy, but they are not that complicated either. The game's difficulty level increases as you progress through the levels, offering a satisfying challenge. To complete a level, you must remove as many numbers from the field as possible. This increases your chances of completing the level. Overall, Sum X is a simple, yet fascinating numbers game that is perfect for anyone who enjoys a good math puzzle game.