MENUOverlapping Pictures
Each picture is drawn on a clear sheet. Lay the second sheet on top of the first without turning it, and color the squares you would see, as in the example. Click a square to color it and click it again to clear it. When you have colored as many squares as the answer needs, a mark shows if it is right. Reload the page for new pictures.
How to add two pictures
Think of each picture as drawn on a sheet of clear plastic. Lay one sheet on top of the other without turning it. Every square that is colored on at least one of the sheets is colored in the answer.
Example 1: no square in common
The first picture has the top left square colored, the second one the bottom right square. Together, both squares are colored.
Example 2: a square on both sheets
The top right square is colored on both sheets. One lies right on top of the other, so the answer has it colored just once: 3 colored squares, not 4.
Symmetry