The sum of 5 consecutive natural numbers is 280, what is the smallest natural number among them?
5个连续自然数的和是280，其中最小的一个自然数是多少．
<gadget id="calculator">280 - 1 - 2 - 3 - 4</gadget>
<output>270</output>

<gadget id="calculator">1 + 1 + 1 + 1 + 1</gadget>
<output>5</output>

<gadget id="calculator">270 / 5</gadget>
<output>54</output>

<result>54</result>