How many small cubes with a side length of 2 cm are needed to form a large cube with a side length of 4 cm.
拼成一个棱长4厘米的大正方体木块，至少需要棱长2厘米的小正方体木块多少个．
<gadget id="calculator">4 / 2</gadget>
<output>2</output>

<gadget id="calculator">2 * 2 * 2</gadget>
<output>8</output>

<result>8</result>