Basics of how to play
Well, let’s try the easiest one.
You can paint with black all nine cells around the number, when it shows “9”.
Look at the number in the very center of this puzzle. It shows “9”.
Then let’s paint with black all nine cells around the number.
Next, look at the number in the cell in bottom right corner. It shows “1”.
This cell is in a corner. That means the number shows how many of “four” cells around it must be painted with black. There is a cell painted with black already. So you can paint all left cells with white.
The number in the cell in bottom left corner shows “1”, too. There is a cell painted with black in four cells around this number. So you can paint all left cells with white again.
Next, the number in the cell at center bottom shows “4”. There are only six cells around it.
Three cells of six already painted with black, two cells with white. So you can paint the cell at center bottom with black.
Next, look at the number in middle left cell. That shows “5”. There are only six cells around it, too.
Three cells (right of the number) of six already painted with black, one with white (under the number). So you can paint two left cells with black.
Next, look at upper right end. The number shows “6”. There are only six cells around the number.
So you can paint all six cells with black.
The number in the cell in the upper left corner shows “4”. A corner has only four cells. So…
You can paint all four cells with black.
At last, the number in the top-center cell shows “5”. Look, five cells around it alreday painted with black. So the cell must be painted with white.
Symbol of heart!
How was it!? Not such difficult is it !? At first, try this one yourself.
>>Try this one
A little harder case
This is a little harder case.
How can I solve it? First, look at the number in very center cell and its upside. They show “1” and “4”.
You can paint black only one cell around “1” (inner side of red lines). So, you must paint three cells (inner side of blue lines) black. Because if you don’t do that, you won’t be able to paint black four cells (Is it a little difficult?).
So, let’s paint those three cells black.
This time, pay attention to “5” on the upper left.
With the same idea, only one cell can be painted black in the part surrounded by the red line. So for “5”, if you don’t paint all four cells surrounded by the blue line, you can’t paint all five cells black.
Next, pay attention to “3” in the upper left corner.
Three cells are already painted black, so the remaining one can be painted white.
Once again, pay attention to the “5” to the right of it. You need to paint one more black, but one is painted white. So…
The remaining one cell can be painted black.
Then, let’s go back to the first “1” in the middle. There is already one cell painted black within the range of the red line. So…
You can paint the remaining 8 squares white!
After that, you can probably solve all the rest.
There are some ways to solve like this, so if you refer to it, you can enjoy “Black or White” even more!