A village has a total of 400 hectares of arable land, 40% of which is dry land, and 80% of the dry land is planted with cotton. How many hectares are there for planting cotton?
某村共有耕地400公顷，其中40%是旱地，在旱地中的80%种棉花，种棉花的地有多少公顷．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">400 * (2/5) * (4/5)</gadget>
<output>128</output>

<result>128</result>