The diameter of the bicycle tire is 40 cm, and it turns 100 times per minute. How many minutes does it take to cover a 6.28-kilometer bridge?
自行车外胎的直径是40厘米，每分钟转100圈，6.28千米的桥，需要多少分钟？
<gadget id="calculator">6.28 * 1_000</gadget>
<output>6_280</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">3.14 * (2/5) * 100</gadget>
<output>125.6</output>

<gadget id="calculator">6_280 / 125.6</gadget>
<output>50</output>

<result>50</result>