A house with a length of 60 decimeters and a width of 50 decimeters is now covered with the same whole square floor tiles, at least how many such floor tiles are needed.
一间房子长为60分米，宽为50分米，现用同样的整块正方形地砖铺满，至少需要多少块这样的地砖．
<gadget id="calculator">10 * 10</gadget>
<output>100</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">60 * (1/2)</gadget>
<output>30</output>

<result>30</result>