The two brothers ran the stairs in a race. When the younger brother ran to the third floor, the older brother happened to run to the fourth floor. According to this calculation, when the younger brother ran to the fifth floor, how many floors did the elder brother run to?
兄弟两人比赛跑楼梯，当弟弟跑到3楼时，哥哥恰好跑到4楼．照这样计算，弟弟跑到5楼时，哥哥跑到多少楼．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">4 * (3/2)</gadget>
<output>6</output>

<gadget id="calculator">6 + 1</gadget>
<output>7</output>

<result>7</result>