step 1
Find out the volume of the rectangular prism
V=L*W*H
L=4 1/2 in=4.5 in
W=2 in
H=1 1/2 in=1.5 in
so
V=(4.5)(2)(1.5)
V=13.5 in3
step 2
Find out the volume of one 1/2 in cube
V=(1/2)^3
V=1/8 in3
step 3
Divide the total volume of the prism by the volume of one 1/2 in cube
13.5/(1/8)=13.5*8=108
therefore
the answer is 108 cubes
