Aunt Wang walks along a 400-meter-long straight track 5 times a day, how many kilometers does she walk every day?
王阿姨每天都沿着一条长400米的直跑道散步走5个来回，她每天走多少千米．
<gadget id="calculator">5 / 1_000</gadget>
<output>1/200 = around 0.005</output>

<gadget id="calculator">400 * 2 * (1/200)</gadget>
<output>4</output>

<result>4</result>