Magic Square 7x7 (tablet 9x9)

Magic Square 7x7 is a game for improving and maintaining your mental arithmetic skills. The goal of the game is to arrange the numbers within the Magic Square into horizontal, vertical and diagonal columns that, added up, all have the same summation.
(Exchanging numbers: Select the number you want to replace. Then select the second with which it has to switch places with.)
The addends will be displayed on the edges of every column. Red marked addends mean, that the summations of the horizontal, vertical and diagonal rows were arranged correctly.
When you solve the smallest Magic Square (3x3) you unlock the next level.
Your results and the time it took you to solve the puzzle can be found on the home menu.
The game has a timer so you can keep track of your progress. All the elements of the Magic Square will be hidden when you pause midway game.
You can adjust your preferred font size with the help of the slide bar.
When leaving the game your progress will be saved. When reentering you can continue playing right where you left off.
The smartphone version offers you levels up to the 7x7 square. On your tablet Magic Square is available way up to level 9x9.