To build a 7,200-meter-long canal, the full length (4/9) has been built, how many meters are left to be repaired?
修一条7200米长的水渠，已经修了全长的(4/9)，还剩多少米没有修？
<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">1 - (4/9)</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">7_200 * (5/9)</gadget>
<output>4_000</output>

<result>4_000</result>