The distance between A and B is 4.2 kilometers, and a car travels the whole distance (5/7), how many meters does it travel?
甲乙两地相距4.2千米，一辆汽车行驶了全程的(5/7)，行驶了多少米？
<gadget id="calculator">4.2 * 1_000</gadget>
<output>4_200</output>

<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">4_200 * (5/7)</gadget>
<output>3_000</output>

<result>3_000</result>