15.1: A Box of Cubes

How many cubes with an edge length of 1 inch fill this box?
 If the cubes had an edge length of 2 inches, would more or fewer cubes be needed to fill the box? Explain how you know.
 If the cubes had an edge length of $\frac 12$ inch, would more or fewer cubes be needed to fill the box? Explain how you know.