On Arbor Day, the fifth grade students planted 56 trees, and the fifth grade students planted fewer trees than the sixth grade students (2/9). How many trees did the sixth graders plant?
植树节那天，五年级同学栽了56棵树，五年级同学比六年级少栽(2/9)．六年级同学栽了多少棵树？
<gadget id="calculator">2 / 9</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">1 - (2/9)</gadget>
<output>7/9 = around 0.777778</output>

<gadget id="calculator">56 / (7/9)</gadget>
<output>72</output>

<result>72</result>