The students planted 200 trees, and (7/10) were planted on the first day, among which (2/5) were planted by the sixth graders. How many trees were planted by the sixth graders on the first day?
同学们植树200棵，第一天植了(7/10)，其中(2/5)是六年级植的，第一天六年级植树多少棵？
<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">200 * (7/10) * (2/5)</gadget>
<output>56</output>

<result>56</result>