Grandpa Zhang’s family has a rectangular vegetable field, 15 meters long and long (4/5) wide. What is the area of this vegetable field in square meters?
张爷爷家有一块长方形的菜地，长15米，宽是长的(4/5)，这块菜地的面积是多少平方米？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">15 * (4/5)</gadget>
<output>12</output>

<gadget id="calculator">15 * 12</gadget>
<output>180</output>

<result>180</result>