How many squares do you see in this picture? It’s been making the rounds on my Facebook friends list. The comments page below are not helpful with ten different answers being posted by hundreds of users.
(Actually on my first count, I got 42, but when I counted up the squares of each size, 2 of them disappeared, so I think I overcounted the first time.)
The breakdown:
1 4X4
4 3X3
11 2 X 2
24 1X1
Note that the size of the cells is not consistent.
I also got 40. 16 of the 1x1, plus 2 more of the 1x1s offset in the middle. 9 2x2. 4 3x3. 1 4x4. And then 8 of the tiny ones made by the offset 1x1s. 16 + 2 + 9 + 4 + 1 + 8 = 40.
Top left, top middle, top right, the smaller 2x2 contained within the top middle.
Middle left, dead centre, middle right.
Bottom left, bottom middle, bottom right, the smaller 2X2 contained within the bottom middle.
And the 1X1 are spoiler + 2(2X2) == 16 + 2(4) == 16 + 8 == 24[/spoiler]
Again, note, the size of the cells is not consistent.
When you have a perfect square of whatever number, you also have the perfect squares of all the other numbers counting up to it. Since this is four squared, you also have three, two and one squared.
16+9+4+1=30
Now you add the two squares in the middle, plus the eight subdivisions of those squares.