A highway is 400 meters long, and (4/5) of the full length has been repaired. How many meters have been repaired?
一条公路全长400米，已修全长的(4/5)．已修多少米？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">400 * (4/5)</gadget>
<output>320</output>

<result>320</result>