Selecting a puzzle: Click the table, type the serial number like 342-20587 and press ENTER.
Each of these puzzles is solved by two or more swaps of numbers in the table.
The target is to make the computed sums (yellow background) equal to the correct sums (white background) by suitable swaps.
Click the the first of the numbers to be swapped and this cell will be painted green and then the second one and this cell is painted red. The numbers are thus swapped.
To start the same game again, click the small blue square in the right bottom corner.
To start a new game, click the small red square.
Clicking of the yellow small square in the right upper corner opens various options. You may change the size of the puzzle (from 2x3 to 6x8) and the degree of difficulty by selecting the maximum number of swaps needed etc. Clicking the yellow square again removes the display of these options.
Further extensions: Survo puzzles combined with picture puzzles.