A ball is dropped from a height of 10m. Every time it hits the ground, the ball bounces back to half of its original height and falls again. How many meters did the ball travel when it hit the ground for the fourth time?
一个皮球从10m高的地方落下，每次着地后皮球都能反弹到原高度的一半，再落下．当这个皮球第4次着地时，它共经过了多少米？
<gadget id="calculator">10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(5/2) / 2</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">10 + 5 + 5 + (5/2) + (5/2) + (5/4) + (5/4)</gadget>
<output>55/2 = around 27.5</output>

<result>55/2 = around 27.5</result>