There are 140 trees to be planted in the sixth grade, which have already been planted (5/7), how many trees are left unplanted?
六年级要栽140棵树，已经栽了(5/7)，还有多少棵没栽？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">1 - (5/7)</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">140 * (2/7)</gadget>
<output>40</output>

<result>40</result>