The objective of 50x50 is to transfer the middle red number to the right side or left side to hopefully create a sum of whatever the black square is. The 8 gray spaces at the bottom are holding spaces for numbers that you can't use at the moment.
The puzzle is solved when both sides reach 50. This game is extremely tough. Why? Because the random red numbers that pop up get very big. Too big to work with. Which means you must store as many small numbers as possible at the bottom.
Another thing to consider: this game takes about 30 minutes to play.
Here's what's weird: I solved the puzzle once, out of 6 or 7 times and felt that aaaaah sense of accomplishment. And yet, there's a leaderboard that records your score. In my view, solving the puzzle is the only goal. If points are going to matter, then the person with the lowest score should be on top. Having a high score indicates lots of muddling mistakes. Maybe I'm wrong on this.