Bats use the ultrasonic waves they send out to determine the distance of their prey. A bat emits ultrasonic waves for 1.8 seconds and receives the reflected ultrasonic waves. It is known that the propagation speed of ultrasonic waves is 340 m/s. Please calculate the distance between the bat and the prey.
蝙蝠利用自己发出的超声波来确定猎物的距离，一只蝙蝠发出超声波1.8秒后接收到反射回来的超声波，已知超声波的传播速度是340米/秒，请你算算蝙蝠与猎物间的距离．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">340 * 1.8</gadget>
<output>612</output>

<gadget id="calculator">(1/2) * 612</gadget>
<output>306</output>

<result>306</result>