How many small cubes are needed to form a large cube with sides of 4 cm from small cubes with side lengths of 2 cm?
用棱长2cm的小正方体木块拼成一个棱长4cm的大正方体，至少需要多少个小正方体．
<gadget id="calculator">2 * 2 * 2</gadget>
<output>8</output>

<result>8</result>