A 10-kilometer-long sand control protection belt has been completed (3/10), how many kilometers are left unconstructed?
建成一条长10千米的治沙防护带，已完工(3/10)，还剩多少千米没有建设？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">10 * (7/10)</gadget>
<output>7</output>

<result>7</result>