Xiao Ming plays a coin toss game. The rule is: toss a coin, and when it falls, it will face up and walk forward 15 steps, and its back will go back 10 steps. Xiao Ming tossed a total of 10 times, and the result is 100 steps forward How many times does the coin land heads?
小明玩抛硬币游戏，规则是：将一枚硬币抛起，落下后正面朝上就向前走15步，背面朝上就向后退10步，小明一共抛了10次，结果向前走了100步，硬币正面朝上多少次？
<gadget id="calculator">15 * 10</gadget>
<output>150</output>

<gadget id="calculator">150 - 100</gadget>
<output>50</output>

<gadget id="calculator">10 + 15</gadget>
<output>25</output>

<gadget id="calculator">50 / 25</gadget>
<output>2</output>

<gadget id="calculator">10 - 2</gadget>
<output>8</output>

<result>8</result>