Let's Make Number Place (Elementary course)
Let's Make Number Place : Step 3
4. Let's fill in 3s.
Next, let's fix 3s. To start with, we set a 3 to the cell shown in the left image.
We need to set one exposed 3 on each of the three pink lines, to make the white 3 valid. We put 3s in the marked exposed cells.
No more 3s should be placed on the exposed cells, and therefore, the marked cell becomes 3.
Samely, this marked cell becomes 3, too.
Since cell E and F are exposed, the only possible cell on the column is cell G. Put 3 there.
We have fixed seven 3s. But in the top left and middle left, there are two possible cells and we can't fix them right now. So let's leave that for the time being and fix other figures.
