Find the volume of the big cube, then divide by the volume of one small cube.<br><br>
&bull; Big cube volume = 15&sup3; = 15 × 15 × 15 = 3375 cm&sup3;<br>
&bull; Small cube volume = 5&sup3; = 5 × 5 × 5 = 125 cm&sup3;<br>
&bull; Number of small cubes = 3375 ÷ 125 = 27<br><br>
Final Answer: 27