The number in the middle of 5 consecutive natural numbers is exactly the sum of these 5 numbers.
5个连续自然数中间一个数正好是这5个数之和的多少．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>