A cube with a side length of 10 cm is placed horizontally in the water, and its height out of the water is exactly half of the side length of the cube. What is the area in square centimeters of the part of the block that is in contact with the air?
将一个棱长10厘米的正方体木块水平地放入水中，它露出水面的高度正好是正方体棱长的一半．这时木块与空气接触部分的面积是多少平方厘米？
<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<gadget id="calculator">10 * 10 * 3</gadget>
<output>300</output>

<result>300</result>