Concrete blocks are typically 8 inches wide, 8 inches tall, and 16 inches long, how many cubic inches is this?

They're just asking for the volume of the block which is length*width*height, since this is a rectangular prisim. So ...

8*8*16 = 64*16 = 1024

The concrete block is 1024 inches cubed or 1024 cubic inches.

1024in^2

You multiply 8 x 8 x 16 and that gives you the answer.