Workers laid bricks for Xiaojuan's house. The living room is 9 meters long and 5 meters wide. (4/5) has been paved. How many square meters has been paved?
工人给小娟家铺砖，客厅长9米，宽5米，已经铺了(4/5)，已经铺了多少平方米？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">9 * 5 * (4/5)</gadget>
<output>36</output>

<result>36</result>