16 with a 4inch by 4inch spuare left over.

A yard is 36 inches, so a square yard is a square with sides length 36 inches. If we are talking about how many sections of squares of side 8 inches are contained within this square, then the answer is 29 x 29 = 841 If you don't see how this answer arises, try putting an 8 inch square in the top left corner of the square yard... then move it down an inch and you have a different square... then another inch is another distinct square and so on, you will get 29 different squares until you reach the bottom. Then start moving these squares an inch to the right each time, and you will find another 29 different squares until to reach the right hand edge of the square yard. Multiplying 29 by 29 therefore gives the total possible combinations of horizontal and vertical locations for your 8 inch squares within the whole square yard. Of course this answer assumes that the "square yard" has dimension of 1 yard by 1 yard. Since "1 square yard" technically only describes the size of the area and not the shape, the "1 square yard" could be an area of 2 yards by 1/2 a yard, 3 yards by 1/3 of a yard, and the number of 8 inch squares would be different in each case.

20.25 is right. 36 inches by 36 inches = 1296 inches divided by 64 (8x8) = 20.25