To answer this question we will compute the volume of the given rectangular prism, and the volume of a cube with a side of 1/6cm, and then we will divide the volume of the given prism by the volume of the cube.
The volume of the given rectangular prism is:
[tex]V_p=\frac{1}{6}cm\times\frac{1}{2}cm\times\frac{1}{2}cm.[/tex]Simplifying the above result we get:
[tex]V_p=\frac{1}{24}cm^3.[/tex]The volume of a cube with a side length of 1/6cm is:
[tex]V_c=(\frac{1}{6}cm)^3=\frac{1}{216}cm^3.[/tex]Therefore we need
[tex]\frac{V_p}{V_c}=\frac{\frac{1}{24}cm^3}{\frac{1}{216}cm^3}=\frac{216}{24}=9[/tex]cubic blocks with a side length of 1/6cm in order to fill the volume of the given prism.
Answer: 9.