90 squares.
10 x 10 = 100 5 x 20 = 100 4 x 25 = 100 2 x 50 = 100
A sixteenth.
200
10 x 11 = 110
You will need 100 of them, but they are rectangles, not squares.
You can get 12.
The answer depends on the units used for "ten x ten". 10 inch x 10 inch or 10 cm x 10 cm?
20 squares x 20 squares = 400 squares
1 x 10 yards is the same as 36 x 360 inches, answer = 12960 square inches.
There is a formula for the "difference of squares." In this case, the answer is (x + 10)(x - 10)
3 3/4 squares.