## Chemistry: Molecular Approach (4th Edition)

$\underline{343}$
The number of cubes can be calculated by dividing the volume of the bigger cube by the volume of the smaller cube. \begin{align} & \text{Number of smaller cubes =}\frac{\text{Volume of 7-cm cube}}{\text{Volume of 1-cm cube}} \\ & =\frac{{{\left( 7\text{ cm} \right)}^{3}}}{{{\left( \text{1 cm} \right)}^{3}}} \\ & =343 \end{align} The number of 1-cm cubes in a 7-cm cube is $\underline{343}$.